use Protobuf library for Python from PyPI

Even with fairly up-to-date packages, many Linux distributions have not
recent enough Python Protobuf packages. It's better to use the PyPI
package, which is published by Google, rather than the distribution
packages.

Ideally, adevtool could handle this (with pinned package version and
hash, and hash-checking), but due to many users encountering this issue,
this change should be reasonable for now.

2 files changed, 61 insertions, 0 deletions

diff --git a/static/build.html b/static/build.html
index 5fb58a8a..ff62d0ec 100644
--- a/static/build.html
+++ b/static/build.html
@@ -250,6 +250,7 @@
                     <p>Additional dependencies for extracting vendor files with adevtool:</p>
 
                     <ul>
+                        <li>Optional: venv module for Python 3</li>
                         <li>protobuf library for Python 3</li>
                         <li>Node.js 18 LTS</li>
                         <li>yarn</li>
@@ -382,11 +383,44 @@ source build/envsetup.sh
 lunch sdk_phone64_x86_64-ap2a-user
 m aapt2</pre>
 
+                    <div class="notice">
+                        <p class="notice-heading">Optional</p>
+
+                        <p>Run the following additional commands once to create a working
+                        environment if your Linux distribution (such as Debian bookworm) doesn't
+                        have the Protobuf library for Python 3 package version (5.)27.2 or later.
+                        This installs the latest library version in a Python 3 virtual
+                        environment.</p>
+
+                        <pre>python3 -m venv venv
+source venv/bin/activate
+pip install protobuf
+deactivate</pre>
+                    </div>
+
+                    <div class="notice">
+                        <p class="notice-heading">Optional</p>
+
+                        <p>If you have installed the Protobuf library in the Python 3 virtual
+                        environment, activate the environment:</p>
+
+                        <pre>source venv/bin/activate</pre>
+                    </div>
+
                     <p>Download, extract and prepare the vendor files:</p>
 
                     <pre>adevtool generate-all -d <var>PIXEL_CODENAME</var></pre>
 
                     <p>Replace <code><var>PIXEL_CODENAME</var></code> with Pixel device codename, which is the same as <a href="#build-targets">build target name</a>.</p>
+
+                    <div class="notice">
+                        <p class="notice-heading">Optional</p>
+
+                        <p>If you have installed the Protobuf library in the Python 3 virtual
+                        environment, deactivate the environment:</p>
+
+                        <pre>deactivate</pre>
+                    </div>
                 </section>
 
                 <section id="setting-up-the-os-build-environment">
diff --git a/static/main.css b/static/main.css
index 80ce0f2e..28e73dc1 100644
--- a/static/main.css
+++ b/static/main.css
@@ -329,6 +329,27 @@ main.normalize {
     margin: 0;
 }
 
+.notice {
+    border-radius: 12px;
+    border: 1px solid #74777f /* outline */;
+    background-color: #dae2f9 /* secondary container */;
+    color: #121c2b /* on secondary container */;
+    padding: 1em;
+    margin-block: 1em;
+}
+
+.notice-heading {
+    margin-block-start: 0;
+}
+
+.notice-heading::before {
+    content: "ⓘ ";
+}
+
+.notice pre {
+    margin-block-end: 0;
+}
+
 /* latin */
 @font-face {
     font-family: Roboto;
@@ -467,4 +488,10 @@ main.normalize {
     var {
         color: #ffb4ab;
     }
+
+    .notice {
+        border-color: #8e9099 /* outline */;
+        background-color: #3e4758 /* secondary container */;
+        color: #dae2f9 /* on secondary container */;
+    }
 }