internal/rosa: handle nil checksum

This defaults to nil, however it did not accept the untyped Azalea nil.

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

1 files changed, 9 insertions, 3 deletions

diff --git a/internal/rosa/state.go b/internal/rosa/state.go
index d937d070..aa03b8ba 100644
--- a/internal/rosa/state.go
+++ b/internal/rosa/state.go
@@ -1274,15 +1274,21 @@ func (ctx *evalContext) pf(
 	}
 
 	if kc != nil {
-		checksum, ok := kc.(string)
-		if !ok {
+		switch checksum := kc.(type) {
+		case string:
+			attr.KnownChecksum = new(mustDecode(checksum))
+			break
+
+		case azalea.Nil:
+			break
+
+		default:
 			err = azalea.TypeError{
 				Concrete: reflect.TypeOf(kc),
 				Asserted: reflect.TypeFor[string](),
 			}
 			return
 		}
-		attr.KnownChecksum = new(mustDecode(checksum))
 	}
 
 	if helper == nil {