electron/docs/development/build-instructions-gn.md

Build Instructions (experimental GN build)

Follow the guidelines below for building Electron with the experimental GN build.

NOTE: The GN build system is in experimental status, and currently only works on macOS and Linux, in debug mode, as a component build.

Prerequisites

See the macOS or Linux build instructions for the requirements for your platform. In addition, you'll need to install depot_tools, the toolset used for fetching Chromium and its dependencies.

Getting the Code

$ mkdir electron-gn && cd electron-gn
$ cat > .gclient <<-GCLIENT
solutions = [
  {
    "url": "https://github.com/electron/electron",
    "managed": False,
    "name": "src/electron",
  },
]
GCLIENT
$ gclient sync --with_branch_heads --with_tags
# This will take a while, go get a coffee.

Building

$ cd src
$ export CHROMIUM_BUILDTOOLS_PATH=`pwd`/buildtools
$ gn gen out/Default --args='root_extra_deps=["//electron"] is_electron_build=true is_component_build=true use_jumbo_build=true v8_promise_internal_field_count=1 v8_typed_array_max_size_in_heap=0'

This will generate all the ninja files needed for the build. You shouldn't have to run gn gen again—if you want to change the build arguments you can run gn args out/Default to bring up an editor.

To build, run ninja with the electron:electron_app target:

$ ninja -C out/Default electron:electron_app
# This will also take a while and probably heat up your lap.

This will build all of what was previously 'libchromiumcontent' (i.e. the content/ directory of chromium and its dependencies, incl. WebKit and V8), so it will take a while.

To speed up subsequent builds, you can use sccache. Add the GN arg cc_wrapper="sccache" by running gn args out/Default to bring up an editor.

The built executable will be under ./out/Default:

$ ./out/Default/Electron.app/Contents/MacOS/Electron
# or, on Linux
$ ./out/Default/electron

Tests

To run the tests, you'll first need to build the test modules against the same version of node.js that was built as part of the build process.

$ (cd electron/spec && npm i --nodedir=../../third_party/electron_node)

Then, run Electron with electron/spec as the argument:

$ ./out/Default/Electron.app/Contents/MacOS/Electron electron/spec

If you're debugging something, it can be helpful to pass some extra flags to the Electron binary:

$ ./out/Default/Electron.app/Contents/MacOS/Electron electron/spec \
  --ci --enable-logging -g 'BrowserWindow module'