Electron Bazel overlay

Build Electron from source using native Bazel actions. This repository owns the electron BCR source overlay: exact source revisions, dependency patch stacks, generators, native libraries and eventually the Electron runtime. App assembly, ASAR, installers, signing and app runtime toolchains belong in a separate rules_electron repository.

Full source-built Electron remains unfinished. Current components include the full patched V8 engine and snapshots, patched libnode, Chromium base, ICU, Perfetto, native networking, typed Mojo IPC, matching Skia with Rust PNG/fontations, native gfx/data packs, display models/wire types, UI events and X11 protocol code, native UI colors/locales and the original WebUI resource pipeline, native font/XML dependencies, libuv, BoringSSL, Node builtin generators, all eight Electron webpack bundles, fuses and eleven Node support libraries (136 C/C++ units; Postject is header-only). Full executable linkage and runtime launch remain unverified. See source status and reproduction.

Layout

Matches perplexityai/rocksdb:

• bcr/: module/source/metadata templates and presubmit configuration.
• bcr/overlay/: maintained Bazel files projected onto upstream Electron source.
• tools/stage_bcr_entry.py: version stamping and overlay integrity generation.
• tests/bcr/: independent consumer, with its own toolchain registration.
• MODULE.bazel: development module, electron_development.

The published source module is electron, versioned with Electron releases. No module has been published. Existing app packaging code was removed from this source-overlay workspace; Git history keeps it available for the future rules repository.

Develop

Use Bazel 9.2.0 or newer. Stage a fresh local registry after changing the overlay:

registry=$(mktemp -d)
python3 tools/stage_bcr_entry.py --source-registry bcr \
  --target-registry "$registry" --module electron --version 39.0.0
python3 tests/validate_bcr.py
bazel build --registry="file://$registry" --registry=https://bcr.bazel.build \
  //:source_components
bazel test --registry="file://$registry" --registry=https://bcr.bazel.build \
  //:source_tests //tests:prepare_source_test

The development workspace consumes the staged electron module, so builds use exactly the source/overlay layout that downstream consumers receive. Use a fresh registry when iterating; staging refuses to overwrite existing version entries.

Check the independent consumer:

cd tests/bcr
bazel test --registry="file://$registry" --registry=https://bcr.bazel.build \
  //:loop_consumer_test @electron//:source_tests

The archive's overlay includes the same consumer for BCR presubmit. Consumer modules register Node 22.20.0, Python 3.11 and LLVM toolchains themselves; the published module does not register toolchains for them.

CI

BuildBuddy configuration and remote execution settings follow formatjs/chromium. Hosted BuildBuddy runs source-component builds, Linux integration tests, five-platform native cross-link probes and the isolated BCR consumer. GitHub Actions runs metadata and registry checks. Windows probes use MSVC; cross-linking does not establish native execution. See CI setup.

Source compatibility

Select Electron release first, then its complete DEPS and ordered patch stacks. This overlay pins Electron 39.0.0, Node 22.20.0, Chromium 142.0.7444.52 and the matching V8 revision. Reuse hermeticbuild/nodejs and formatjs/chromium build machinery while preserving Electron's patched dependency closure. Host Node build tools stay separate from Electron's embedded target Node.

Repository code is MIT. Adapted registry staging code is Apache-2.0; see NOTICE. Upstream sources retain their own licenses.