From b125c96352d251effbc52a29aef63449940e9bb7 Mon Sep 17 00:00:00 2001
From: MarkZ <markzipan@google.com>
Date: Fri, 21 Nov 2025 14:15:24 -0800
Subject: [PATCH 1/2] Fix module_builder reading DDC modules for non-primary
 dart libraries.

---
 build_modules/lib/src/module_builder.dart | 24 ++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/build_modules/lib/src/module_builder.dart b/build_modules/lib/src/module_builder.dart
index f421ff313..380c9ab5f 100644
--- a/build_modules/lib/src/module_builder.dart
+++ b/build_modules/lib/src/module_builder.dart
@@ -55,18 +55,19 @@ class ModuleBuilder implements Builder {
     var outputModule = metaModule.modules.firstWhereOrNull(
       (m) => m.primarySource == buildStep.inputId,
     );
-    final serializedLibrary = await buildStep.readAsString(
-      buildStep.inputId.changeExtension(moduleLibraryExtension),
-    );
-    final libraryModule = ModuleLibrary.deserialize(
-      buildStep.inputId,
-      serializedLibrary,
-    );
-    final scratchSpace = await buildStep.fetchResource(scratchSpaceResource);
-    if (outputModule == null && libraryModule.hasMain) {
-      outputModule = metaModule.modules.firstWhere(
-        (m) => m.sources.contains(buildStep.inputId),
+    if (outputModule == null) {
+      final serializedLibrary = await buildStep.readAsString(
+        buildStep.inputId.changeExtension(moduleLibraryExtension),
+      );
+      final libraryModule = ModuleLibrary.deserialize(
+        buildStep.inputId,
+        serializedLibrary,
       );
+      if (libraryModule.hasMain) {
+        outputModule = metaModule.modules.firstWhere(
+          (m) => m.sources.contains(buildStep.inputId),
+        );
+      }
     }
     if (outputModule == null) return;
     final modules = await buildStep.fetchResource(moduleCache);
@@ -76,6 +77,7 @@ class ModuleBuilder implements Builder {
       outputModule,
     );
     if (usesWebHotReload) {
+      final scratchSpace = await buildStep.fetchResource(scratchSpaceResource);
       // All sources must be declared before the Frontend Server is invoked, as
       // it only accepts the main entrypoint as its compilation target.
       await buildStep.trackStage(

From 6298dabdce31692aecbcb57483f630c1a3ebd728 Mon Sep 17 00:00:00 2001
From: MarkZ <markzipan@google.com>
Date: Fri, 21 Nov 2025 14:21:25 -0800
Subject: [PATCH 2/2] bumping ver

---
 build_modules/CHANGELOG.md | 3 +++
 build_modules/pubspec.yaml | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/build_modules/CHANGELOG.md b/build_modules/CHANGELOG.md
index 1e5e614ae..8ee473f28 100644
--- a/build_modules/CHANGELOG.md
+++ b/build_modules/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 5.1.4
+- Fix module_builder reading DDC modules for non-primary dart libraries.
+
 ## 5.1.3
 
 - Allow `analyzer` 9.0.0.
diff --git a/build_modules/pubspec.yaml b/build_modules/pubspec.yaml
index 71090f69d..32d7132aa 100644
--- a/build_modules/pubspec.yaml
+++ b/build_modules/pubspec.yaml
@@ -1,5 +1,5 @@
 name: build_modules
-version: 5.1.3
+version: 5.1.4
 description: >-
   Builders to analyze and split Dart code into individually compilable modules
   based on imports.