v3.0.0

Breaking changes

• The action now runs on the node24 runtime. GitHub-hosted runners are unaffected; self-hosted runners must be v2.327.1 or newer.
• The cflags input now applies only to the micropython Unix port build, not to mpy-cross. mpy-cross's fixed feature configuration fails to compile with many otherwise-valid MicroPython feature flags; its meaningful options (target architecture, emitter, optimization level) are runtime CLI flags and are unaffected. CFLAGS_EXTRA is still exported to all subsequent steps of the job.
• The MicroPython repository is cloned to os.homedir()/micropython instead of a hardcoded /home/runner/micropython. This is unchanged on GitHub-hosted runners; on self-hosted runners, use the MPY_DIR environment variable rather than a hardcoded path.

New features

• New outputs: cache-hit ('true'/'false') and sha (the resolved MicroPython commit SHA), useful for keying your own caches off the exact MicroPython version.
• New submodules input (default true): submodules are now initialized even on cache hits, so MPY_DIR works for natmod-style builds on warm runs (previously these passed on the first run and failed on cached re-runs). Set to false to make cached runs ~30 seconds faster if you only need the micropython/mpy-cross binaries.
• Tag references are fetched with a fast shallow clone; branches and commit SHAs use a full clone so the built interpreter reports an accurate git describe-based version string.

Fixes

• Git commands are invoked with argument arrays, preventing argument injection via the repository/reference inputs.
• A cache-save race between concurrent jobs building the same configuration no longer fails an otherwise-successful build.
• Build parallelism comes from os.cpus() instead of nproc, for self-hosted portability.

Full Changelog: v2...v3.0.0

v2.4.0

Maintenance release — no runtime or input changes. Workflows on @v2 need no updates. Upgraded the GitHub Actions toolkit (@actions/cache 6.1.0, @actions/core 3.0.1, @actions/exec/@actions/io 2.0.0) and@vercel/ncc 0.44.0; migrated to ESM (#43).

Full Changelog: v2...v2.4.0

v2.3.0

What's Changed

• Bump @vercel/ncc from 0.38.1 to 0.38.3
• Bump @actions/core from 1.10.1 to 1.11.1
• Bump @actions/cache from 3.2.4 to 4.0.0

Full Changelog: v2...v2.3.0

v2.2.0

What's Changed

• Allow user to specify cflags. by @BrianPugh in #16

Full Changelog: v2...v2.2.0

v2.1.0

Features

• Add ${MPY_DIR}/mpy-cross/build/mpy-cross to the cache paths; some tools (somewhat) inappropriately hardcode this location for the mpy-cross executable.

Full Changelog: v2.0.0...v2.1.0

v2.0.0

What's Changed

• Update to node 20 by @BrianPugh in #13

Full Changelog: v1.0.6...v2.0.0

v1.0.6

What's Changed

• Fix/reference param issue by @brendancolevalley in #10

New Contributors

• @brendancolevalley made their first contribution in #10

Full Changelog: v1...v1.0.6

v1.0.5 - Speed Improvements

Features

• No longer cache the micropython repository folder. We have to clone it anyways, and I don't believe the build files are useful to anyone downstream. This shrinks the cache from ~140MB to ~400KB, substantially speeding up cache compression, downloads, and uploads.

v1.0.4 - More cache fixes

Bug Fixes

• Mitigates upstream caching issues described in actions/toolkit#1377, actions/toolkit#1376
• Shorted cache key while still maintaining uniqueness.

v1.0.3 - Move out of GITHUB_WORKSPACE

Bugfixes

• Moved the micropython repository folder out of GITHUB_WORKSPACE to not pollute the workspace.