Running a build

Running a build

From the web UI

1. Open the repository's Actions tab.
2. Pick a workflow from the left-hand list.
3. Run workflow → leave every input blank → Run workflow.

Blank inputs mean "build the latest stable Chromium milestone". The run starts by printing what it resolved, and writes the same to the job summary:

WebRTC source

Branch	branch-heads/7977
Chromium milestone	M152
Resolved by	auto-detected (latest stable Chromium milestone)

When it finishes, the artifact is at the bottom of the run page.

From the command line

gh workflow run WebRtcNativeWindowsDynamicLib.yml
gh workflow run WebRtcNativeAndroidLib.yml -f webrtc_branch=7977
gh run watch
gh run download <run-id>

Inputs

Present on every workflow:

Input	Default	Notes
webrtc_branch	(empty)	WebRTC branch-head, e.g. 7977. Empty means latest stable.

Note this is the branch number (7977), not the Chromium milestone (152); https://chromiumdash.appspot.com/branches maps one to the other. See Branch selection for why there is only one input.

Platform-specific:

Workflow	Input	Default	Options
Windows ×2	target_cpu	x64	x64, x86, arm64
Linux ×2	target_cpu	x64	x64, arm64, arm
macOS ×2	target_cpu	arm64	arm64, x64
Android	arch	(empty = all ABIs)	space-separated, e.g. arm64-v8a x86_64
iOS	arch	device:arm64 simulator:arm64 simulator:x64	see Workflow reference
Mac Catalyst	arch	catalyst:arm64 catalyst:x64	see Workflow reference
iOS, Mac Catalyst	build_config	release	release, debug

macOS defaults to arm64 because macos-latest runners are Apple silicon. Select x64 for a library that runs on Intel Macs.

Artifacts

Names carry the milestone and branch, so downloads from different runs never collide:

Workflow	Artifact	Contents
WindowsStaticLib	webrtc-windows-x64-static-m152-7977	webrtc.lib
WindowsDynamicLib	webrtc-windows-x64-dynamic-m152-7977	webrtc.dll, webrtc.dll.lib, webrtc.dll.pdb
LinuxStaticLib	webrtc-linux-x64-static-m152-7977	libwebrtc.a
LinuxSharedLib	webrtc-linux-x64-shared-m152-7977	libwebrtc.so
MacOsStaticLib	webrtc-macos-arm64-static-m152-7977	libwebrtc.a
MacOsSharedLib	webrtc-macos-arm64-shared-m152-7977	libwebrtc.dylib
AndroidLib	webrtc-android-m152-7977	libwebrtc.aar
IosLib	webrtc-ios-m152-7977	WebRTC.xcframework.zip (iOS slices)
MacCatalystLib	webrtc-maccatalyst-m152-7977	WebRTC.xcframework.zip (Catalyst slices)

Retention is 30 days. Download anything you intend to keep, or attach it to a release.

How long it takes

Roughly an hour per workflow, dominated by gclient sync (a ~30 GB checkout) and the compile. The workflows build the webrtc target specifically rather than the whole tree, and disable tests, tools and examples, which cuts a substantial amount of both time and disk off the old behaviour.

Runs are capped at timeout-minutes: 360.

Running several at once

Each workflow is independent and they can run in parallel, subject to your account's concurrency limits. macOS runners are the scarcest and the most expensive; queue those deliberately.

Reproducing an earlier build

Read the branch number from the old run's job summary and pass it explicitly:

gh workflow run WebRtcNativeLinuxSharedLib.yml -f webrtc_branch=7922

This is exact for the WebRTC source. It is not a hermetic reproduction — the runner image, Xcode/MSVC version and depot_tools all move independently.