build: create a symlink to src/buildtools during sync

Assisted-by: Claude Opus 4.6

.devcontainer/on-create-command.sh

@@ -54,7 +54,6 @@ if [ ! -f $buildtools/configs/evm.testing.json ]; then
                 \"out\": \"Testing\"
             },
             \"env\": {
-                \"CHROMIUM_BUILDTOOLS_PATH\": \"/workspaces/gclient/src/buildtools\",
                 \"GIT_CACHE_PATH\": \"/workspaces/gclient/.git-cache\"
             },
             \"\$schema\": \"file:///home/builduser/.electron_build_tools/evm-config.schema.json\",

.github/workflows/pipeline-electron-lint.yml

@@ -57,9 +57,6 @@ jobs:
         @Subdir src/buildtools/linux64
         gn/gn/linux-amd64 $gn_version
         CIPD
-
-        buildtools_path="$(pwd)/src/buildtools"
-        echo "CHROMIUM_BUILDTOOLS_PATH=$buildtools_path" >> $GITHUB_ENV
     - name: Download clang-format Binary
       shell: bash
       run: |
@@ -80,11 +77,10 @@ jobs:
     - name: Run Lint
       shell: bash
       run: |
-        # gn.py tries to find a gclient root folder starting from the current dir.
-        # When it fails and returns "None" path, the whole script fails. Let's "fix" it.
-        touch .gclient
-        # Another option would be to checkout "buildtools" inside the Electron checkout,
-        # but then we would lint its contents (at least gn format), and it doesn't pass it.
+        # Clean things up so `depot_tools/gclient_paths.py` finds src/buildtools properly
+        echo '' > .gclient
+        rm -f .gclient_entries
+        ln -s src/buildtools buildtools
 
         cd src/electron
         node script/yarn.js install --immutable

.github/workflows/pipeline-segment-electron-build.yml

@@ -189,8 +189,6 @@ jobs:
       run: |
         (cd src/electron && git checkout .) && node src/electron/script/generate-deps-hash.js
         echo "DEPSHASH=$(cat src/electron/.depshash)" >> $GITHUB_ENV
-    - name: Add CHROMIUM_BUILDTOOLS_PATH to env
-      run: echo "CHROMIUM_BUILDTOOLS_PATH=$(pwd)/src/buildtools" >> $GITHUB_ENV
     - name: Free up space (macOS)
       if: ${{ inputs.target-platform == 'macos' }}
       uses: ./src/electron/.github/actions/free-space-macos

.github/workflows/pipeline-segment-electron-clang-tidy.yml

@@ -111,8 +111,6 @@ jobs:
       run: |
         (cd src/electron && git checkout .) && node src/electron/script/generate-deps-hash.js
         echo "DEPSHASH=$(cat src/electron/.depshash)" >> $GITHUB_ENV
-    - name: Add CHROMIUM_BUILDTOOLS_PATH to env
-      run: echo "CHROMIUM_BUILDTOOLS_PATH=$(pwd)/src/buildtools" >> $GITHUB_ENV
     - name: Checkout Electron
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
       with:

.github/workflows/pipeline-segment-electron-gn-check.yml

@@ -112,8 +112,6 @@ jobs:
       run: |
         (cd src/electron && git checkout .) && node src/electron/script/generate-deps-hash.js
         echo "DEPSHASH=$(cat src/electron/.depshash)" >> $GITHUB_ENV
-    - name: Add CHROMIUM_BUILDTOOLS_PATH to env
-      run: echo "CHROMIUM_BUILDTOOLS_PATH=$(pwd)/src/buildtools" >> $GITHUB_ENV
     - name: Checkout Electron
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
       with:
@@ -128,6 +126,11 @@ jobs:
         git pack-refs
     - name: Run GN Check for ${{ inputs.target-archs }}
       run: |
+        # `depot_tools/gclient_paths.py` tries to find a gclient root folder starting from the current dir.
+        # We also need to set up a symlink to src/buildtools so that `build-tools` can find it properly.
+        touch .gclient
+        ln -s src/buildtools buildtools
+
         for target_cpu in ${{ inputs.target-archs }}
         do
           e init -f --root=$(pwd) --out=Default ${{ inputs.gn-build-type }} --import ${{ inputs.gn-build-type }} --target-cpu $target_cpu --remote-build none

.github/workflows/pipeline-segment-electron-publish.yml

@@ -202,8 +202,6 @@ jobs:
           src/electron/script/generate-deps-hash.js
 
           echo "DEPSHASH=$(cat src/electron/.depshash)" >> $GITHUB_ENV
-      - name: Add CHROMIUM_BUILDTOOLS_PATH to env
-        run: echo "CHROMIUM_BUILDTOOLS_PATH=$(pwd)/src/buildtools" >> $GITHUB_ENV
       - name: Free up space (macOS)
         if: ${{ inputs.target-platform == 'macos' }}
         uses: ./src/electron/.github/actions/free-space-macos

DEPS

@@ -155,6 +155,15 @@ hooks = [
       'import os, subprocess; os.chdir(os.path.join("src", "electron")); subprocess.check_call(["node", ".yarn/releases/yarn-4.12.0.cjs", "install", "--immutable"]);',
     ],
   },
+  {
+    'name': 'buildtools_symlink',
+    'condition': 'checkout_chromium and process_deps',
+    'pattern': 'src/electron',
+    'action': [
+      'python3',
+      'src/electron/script/create-buildtools-symlink.py',
+    ],
+  },
   {
     'name': 'sysroot_arm',
     'pattern': '.',

docs/development/build-instructions-gn.md

@@ -173,27 +173,6 @@ $ gclient sync -f
 
 ### Building
 
-**Set the environment variable for chromium build tools**
-
-On Linux & MacOS
-
-```sh
-$ cd src
-$ export CHROMIUM_BUILDTOOLS_PATH=`pwd`/buildtools
-```
-
-On Windows:
-
-```sh
-# cmd
-$ cd src
-$ set CHROMIUM_BUILDTOOLS_PATH=%cd%\buildtools
-
-# PowerShell
-$ cd src
-$ $env:CHROMIUM_BUILDTOOLS_PATH = "$(Get-Location)\buildtools"
-```
-
 **To generate Testing build config of Electron:**
 
 On Linux & MacOS

script/create-buildtools-symlink.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""Create a buildtools symlink in the gclient root directory.
+
+This enables gclient_paths.py to locate buildtools without needing the
+CHROMIUM_BUILDTOOLS_PATH environment variable.
+"""
+
+import os
+import sys
+
+
+def main():
+  electron_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+  src_dir = os.path.dirname(electron_dir)
+  gclient_root = os.path.dirname(src_dir)
+
+  source = os.path.join(src_dir, 'buildtools')
+  link_name = os.path.join(gclient_root, 'buildtools')
+
+  if not os.path.isdir(source):
+    print(f'buildtools not found at {source}', file=sys.stderr)
+    return 1
+
+  # Already a symlink - verify it points to the right place.
+  if os.path.islink(link_name):
+    if os.path.realpath(link_name) == os.path.realpath(source):
+      return 0
+    os.remove(link_name)
+  elif os.path.exists(link_name):
+    # A real file or directory we shouldn't clobber.
+    print(f'{link_name} already exists and is not a symlink',
+          file=sys.stderr)
+    return 1
+
+  rel = os.path.relpath(source, gclient_root)
+  try:
+    os.symlink(rel, link_name, target_is_directory=True)
+  except OSError as e:
+    print(f'Failed to create symlink {link_name} -> {rel}: {e}',
+          file=sys.stderr)
+    if sys.platform == 'win32':
+      print('On Windows, creating symlinks requires Developer Mode '
+            'or administrator privileges.', file=sys.stderr)
+    return 1
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())

script/gn-check.js

@@ -7,14 +7,11 @@ $ node ./script/gn-check.js [--outDir=dirName]
 const minimist = require('minimist');
 
 const cp = require('node:child_process');
-const path = require('node:path');
 
 const args = minimist(process.argv.slice(2), { string: ['outDir'] });
 
 const { getDepotToolsEnv, getOutDir } = require('./lib/utils');
 
-const SOURCE_ROOT = path.normalize(path.dirname(__dirname));
-
 const OUT_DIR = getOutDir({ outDir: args.outDir });
 if (!OUT_DIR) {
   throw new Error('No viable out dir: one of Debug, Testing, or Release must exist.');
@@ -22,7 +19,6 @@ if (!OUT_DIR) {
 
 const env = {
   ...getDepotToolsEnv(),
-  CHROMIUM_BUILDTOOLS_PATH: path.resolve(SOURCE_ROOT, '..', 'buildtools'),
   DEPOT_TOOLS_WIN_TOOLCHAIN: '0'
 };
 

script/lib/util.py

@@ -233,9 +233,4 @@ def get_depot_tools_env():
   if depot_tools_env is None:
     raise RuntimeError("Couldn't find depot_tools, ensure it's on your PATH")
 
-  if 'CHROMIUM_BUILDTOOLS_PATH' not in depot_tools_env:
-    raise RuntimeError(
-      'CHROMIUM_BUILDTOOLS_PATH environment variable must be set'
-    )
-
   return depot_tools_env

script/lib/utils.js

@@ -194,10 +194,6 @@ function getDepotToolsEnv() {
     throw new Error("Couldn't find depot_tools, ensure it's on your PATH");
   }
 
-  if (!('CHROMIUM_BUILDTOOLS_PATH' in depotToolsEnv)) {
-    throw new Error('CHROMIUM_BUILDTOOLS_PATH environment variable must be set');
-  }
-
   return depotToolsEnv;
 }
 

script/lint.js

@@ -116,13 +116,11 @@ const LINTERS = [
     roots: ['shell'],
     test: (filename) => filename.endsWith('.cc') || (filename.endsWith('.h') && !isObjCHeader(filename)),
     run: (opts, filenames) => {
-      const env = {
-        ...getDepotToolsEnv(),
-        CHROMIUM_BUILDTOOLS_PATH: path.resolve(ELECTRON_ROOT, '..', 'buildtools')
-      };
       const clangFormatFlags = opts.fix ? ['--fix'] : [];
       for (const chunk of chunkFilenames(filenames)) {
-        spawnAndCheckExitCode('python3', ['script/run-clang-format.py', ...clangFormatFlags, ...chunk], { env });
+        spawnAndCheckExitCode('python3', ['script/run-clang-format.py', ...clangFormatFlags, ...chunk], {
+          env: getDepotToolsEnv()
+        });
         cpplint([`--filter=${CPPLINT_FILTERS.join(',')}`, ...chunk]);
       }
     }
@@ -132,13 +130,9 @@ const LINTERS = [
     roots: ['shell'],
     test: (filename) => filename.endsWith('.mm') || (filename.endsWith('.h') && isObjCHeader(filename)),
     run: (opts, filenames) => {
-      const env = {
-        ...getDepotToolsEnv(),
-        CHROMIUM_BUILDTOOLS_PATH: path.resolve(ELECTRON_ROOT, '..', 'buildtools')
-      };
       const clangFormatFlags = opts.fix ? ['--fix'] : [];
       spawnAndCheckExitCode('python3', ['script/run-clang-format.py', '-r', ...clangFormatFlags, ...filenames], {
-        env
+        env: getDepotToolsEnv()
       });
       const filter = [...CPPLINT_FILTERS, '-readability/braces'];
       cpplint(['--extensions=mm,h', `--filter=${filter.join(',')}`, ...filenames]);
@@ -175,7 +169,6 @@ const LINTERS = [
         .map((filename) => {
           const env = {
             ...getDepotToolsEnv(),
-            CHROMIUM_BUILDTOOLS_PATH: path.resolve(ELECTRON_ROOT, '..', 'buildtools'),
             DEPOT_TOOLS_WIN_TOOLCHAIN: '0'
           };
           const args = ['format', filename];