Merge pull request #55 from toyota-connected/fix/image-native-compiler

fix(cross): bake a native compiler into the toolchain image; surface augment errors

lib/src/cross/dockerfile_emitter.dart

@@ -43,13 +43,14 @@ class ToolchainImage {
 #   container: <tag>
 #   emb cross <manifest> --target <name> --build -w $workspace
 FROM $fromImage
-# Build tooling: cmake/ninja/meson/make/pkg-config + the embedder's host codegen
+# Build tooling: cmake/ninja/meson/pkg-config + the embedder's host codegen
 # (wayland-scanner via libwayland-bin; git/curl for the engine-header fetch).
-# meson builds `augment` libraries (e.g. libdisplay-info) into the sysroot.
+# build-essential gives meson a native (build-machine) compiler — required to
+# configure even a cross build when rebuilding `augment` libs (libdisplay-info).
 RUN apt-get update \\
  && apt-get install -y --no-install-recommends \\
-      cmake ninja-build meson make pkg-config tar xz-utils rsync ca-certificates \\
-      libwayland-bin git curl \\
+      cmake ninja-build meson build-essential pkg-config \\
+      tar xz-utils rsync ca-certificates libwayland-bin git curl \\
  && rm -rf /var/lib/apt/lists/*
 ENV FLUTTER_WORKSPACE=$workspace
 COPY toolchain $dir/toolchain

lib/src/cross/overlay_builder.dart

@@ -212,7 +212,12 @@ class OverlayBuilder {
   /// actionable rather than a bare "failed to build into overlay".
   void _check(AugmentLib lib, String step, ProcessResult r) {
     if (r.exitCode == 0) return;
-    final detail = '${r.stderr}'.trim();
+    // meson/cmake write diagnostics to stdout as often as stderr, so surface
+    // both — otherwise a "meson setup failed (exit 1)" is undebuggable.
+    final detail = [
+      '${r.stderr}',
+      '${r.stdout}',
+    ].map((s) => s.trim()).where((s) => s.isNotEmpty).join('\n');
     throw OverlayBuildException(
       '${lib.pkg}: $step failed (exit ${r.exitCode})'
       '${detail.isEmpty ? '' : '\n$detail'}',

test/src/cross/dockerfile_emitter_test.dart

@@ -22,6 +22,7 @@ void main() {
       expect(df, contains('cmake'));
       expect(df, contains('ninja-build'));
       expect(df, contains('meson')); // builds augment libs (libdisplay-info)
+      expect(df, contains('build-essential')); // native cc for meson configure
       expect(df, contains('libwayland-bin')); // wayland-scanner for wayland-egl
       expect(df, contains('FROM ${ToolchainImage.defaultFrom}'));
       expect(df, contains('emb.triple="aarch64-none-linux-gnu"'));