Limrun Bazel

Bazel on Limrun's build plane

lim bazel setup points a Bazel workspace at Limrun's build plane: Apple actions run on Limrun's Macs, Android actions on Limrun's Linux workers, and every build of the organization shares one remote cache. Bazel keeps running where it already does; no local Xcode or Android SDK is needed for the remote actions.

Auth and CLI

Install with npm: npm install --global lim (0.44.0 or later). The npm package also installs lim-bazel-credentials, the credential helper Bazel calls; the standalone tarball and DotSlash builds do not put it on PATH, so Bazel cannot authenticate with them. Auth is lim login or LIM_API_KEY (it may already be set even when the shell does not show it; check before asking). The helper reads only lim login or LIM_API_KEY, never a key passed with --api-key. The CLI is the source of truth: if a flag errors, check lim bazel setup --help instead of guessing.

Set up

Run inside the workspace (it walks up to the directory with MODULE.bazel):

lim bazel setup

It needs Bazel 8 or later and rules_apple or rules_android in the root MODULE.bazel. It writes a gitignored .limrun/ with the --config=limrun configuration and adds a try-import to .bazelrc. Nothing secret is written: Bazel asks the credential helper for a short-lived token.

• Region: setup picks the closest region that runs a build plane. --region <name> pins one.
• Android: Linux workers need rules_cc, rules_java, protobuf and hermetic_android_toolchains in the root MODULE.bazel. Setup prints the missing lines and asks; --yes adds them without asking. Without a terminal and without --yes it stops and prints the lines, so pass --yes in scripts and CI.
• Java runtime: a --java_runtime_version already in .bazelrc is kept; otherwise the limrun config uses remotejdk_17.
• Re-run setup after upgrading the CLI or when the workspace starts using Apple or Android rules. Do not hand-edit .limrun/.

Build

bazel build --config=limrun //your:target

Build actions run remotely and Bazel downloads only the top-level outputs (the .apk or .ipa). Without --config=limrun, Bazel builds as before. Own flags for the limrun path go in user.limrun.bazelrc at the workspace root; the generated config imports it last and it survives re-running setup.

In CI: install lim from npm, set LIM_API_KEY as a secret, run lim bazel setup --yes, then build with --config=limrun.

Run the app

Build for the simulator or emulator, then install the .ipa or .apk path Bazel prints:

lim ios create && lim ios sync bazel-bin/App/App.ipa
lim android create && lim android install-app bazel-bin/app/app.apk

Re-run lim ios sync after each rebuild; it sends only the difference. To drive the running app, use limrun-ios-simulator or limrun-android-emulator.

Check results

The console's Bazel page (https://console.limrun.com/bazel) lists the organization's builds from every region, with live output for running builds and the remote cache hit rate per build.

When a build fails

• Bazel cannot authenticate or reports a credential helper error: check that lim-bazel-credentials is on PATH (npm install) and that lim login or LIM_API_KEY is set where Bazel runs.
• "the build plane could not start a worker" or "no linux worker is free": transient capacity; retry the build.
• Missing @androidsdk or Android toolchain errors: the MODULE.bazel lines are missing. Re-run lim bazel setup and accept them.
• Each region keeps its own cache: the first build in a new region starts cold.