container/stub: export stub helpers

These are very useful in many packages containing relatively large amount of code making calls to difficult or impossible to stub functions.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 608 insertions, 606 deletions

diff --git a/container/initdev_test.go b/container/initdev_test.go
index 32931614..e3cc9d50 100644
--- a/container/initdev_test.go
+++ b/container/initdev_test.go
@@ -3,6 +3,8 @@ package container
 import (
 	"os"
 	"testing"
+
+	"hakurei.app/container/stub"
 )
 
 func TestMountDevOp(t *testing.T) {
@@ -10,745 +12,745 @@ func TestMountDevOp(t *testing.T) {
 		{"mountTmpfs", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, stub.UniqueError(27)},
+		}, stub.UniqueError(27)},
 
 		{"ensureFile null", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(26)},
+		}, stub.UniqueError(26)},
 
 		{"bindMount null", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, stub.UniqueError(25)},
+		}, stub.UniqueError(25)},
 
 		{"ensureFile zero", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(24)},
+		}, stub.UniqueError(24)},
 
 		{"bindMount zero", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, stub.UniqueError(23)},
+		}, stub.UniqueError(23)},
 
 		{"ensureFile full", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(22)},
+		}, stub.UniqueError(22)},
 
 		{"bindMount full", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, stub.UniqueError(21)},
+		}, stub.UniqueError(21)},
 
 		{"ensureFile random", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(20)},
+		}, stub.UniqueError(20)},
 
 		{"bindMount random", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, stub.UniqueError(19)},
+		}, stub.UniqueError(19)},
 
 		{"ensureFile urandom", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(18)},
+		}, stub.UniqueError(18)},
 
 		{"bindMount urandom", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, stub.UniqueError(17)},
+		}, stub.UniqueError(17)},
 
 		{"ensureFile tty", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(16)},
+		}, stub.UniqueError(16)},
 
 		{"bindMount tty", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, stub.UniqueError(15)},
+		}, stub.UniqueError(15)},
 
 		{"symlink stdin", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, stub.UniqueError(14)},
+		}, stub.UniqueError(14)},
 
 		{"symlink stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, stub.UniqueError(13)},
+		}, stub.UniqueError(13)},
 
 		{"symlink stderr", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, stub.UniqueError(12)},
+		}, stub.UniqueError(12)},
 
 		{"symlink fd", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, stub.UniqueError(11)},
+		}, stub.UniqueError(11)},
 
 		{"symlink kcore", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, stub.UniqueError(10)},
+		}, stub.UniqueError(10)},
 
 		{"symlink ptmx", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, stub.UniqueError(9)},
+		}, stub.UniqueError(9)},
 
 		{"mkdir shm", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, stub.UniqueError(8)},
+		}, stub.UniqueError(8)},
 
 		{"mkdir devpts", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, stub.UniqueError(7)},
+		}, stub.UniqueError(7)},
 
 		{"mount devpts", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, stub.UniqueError(6)},
+		}, stub.UniqueError(6)},
 
 		{"ensureFile stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, stub.UniqueError(5)},
+		}, stub.UniqueError(5)},
 
 		{"readlink stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "", errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "", stub.UniqueError(4)},
+		}, stub.UniqueError(4)},
 
 		{"bindMount stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, stub.UniqueError(3)},
+		}, stub.UniqueError(3)},
 
 		{"mkdir mqueue", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, stub.UniqueError(2)},
+		}, stub.UniqueError(2)},
 
 		{"mount mqueue", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, stub.UniqueError(1)},
+		}, stub.UniqueError(1)},
 
 		{"success no session", &Params{ParentPerm: 0755}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
 			Write:  true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0755)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0755)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0755)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0755)}, nil, nil},
-			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0755)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0755)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0755)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0755)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0755)}, nil, nil},
+			{"mount", stub.ExpectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
 		}, nil},
 
 		{"success no tty", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
 			Write:  true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, false, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, false, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
 		}, nil},
 
 		{"remount", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"remount", expectArgs{"/sysroot/dev", uintptr(1)}, nil, errUnique},
-		}, errUnique},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"remount", stub.ExpectArgs{"/sysroot/dev", uintptr(1)}, nil, stub.UniqueError(0)},
+		}, stub.UniqueError(0)},
 
 		{"success no mqueue", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"remount", expectArgs{"/sysroot/dev", uintptr(1)}, nil, nil},
-			{"mountTmpfs", expectArgs{"tmpfs", "/sysroot/dev/shm", uintptr(0x6), 0, os.FileMode(01777)}, nil, nil},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"remount", stub.ExpectArgs{"/sysroot/dev", uintptr(1)}, nil, nil},
+			{"mountTmpfs", stub.ExpectArgs{"tmpfs", "/sysroot/dev/shm", uintptr(0x6), 0, os.FileMode(01777)}, nil, nil},
 		}, nil},
 
 		{"success rw", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
 			Write:  true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
 		}, nil},
 
 		{"success", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 			Mqueue: true,
-		}, nil, nil, []kexpect{
-			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
-			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
-			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
-			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
-			{"isatty", expectArgs{1}, true, nil},
-			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
-			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
-			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
-			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
-			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
-			{"remount", expectArgs{"/sysroot/dev", uintptr(1)}, nil, nil},
-			{"mountTmpfs", expectArgs{"tmpfs", "/sysroot/dev/shm", uintptr(0x6), 0, os.FileMode(01777)}, nil, nil},
+		}, nil, nil, []stub.Call{
+			{"mountTmpfs", stub.ExpectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", stub.ExpectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", stub.ExpectArgs{1}, true, nil},
+			{"ensureFile", stub.ExpectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", stub.ExpectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", stub.ExpectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"mkdir", stub.ExpectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, nil},
+			{"mount", stub.ExpectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
+			{"remount", stub.ExpectArgs{"/sysroot/dev", uintptr(1)}, nil, nil},
+			{"mountTmpfs", stub.ExpectArgs{"tmpfs", "/sysroot/dev/shm", uintptr(0x6), 0, os.FileMode(01777)}, nil, nil},
 		}, nil},
 	})