strace github-cross-testing

A reusable GitHub Actions workflow for continuous cross-architecture testing of strace on rarely-tested CPU architectures. It builds a cross toolchain and minimal root filesystem with Buildroot (version pinned in ci/buildroot-version), cross-compiles strace and its test suite, boots the target under QEMU system emulation, and runs make check in the guest.

Usage from strace/strace

# .github/workflows/cross.yml
name: cross
on: [push, pull_request]
jobs:
  cross:
    uses: gabifalk/strace-github-cross-testing/.github/workflows/cross.yml@v1

This tests the pushed commit. To restrict arches or shards:

    with:
      arches: 'm68k s390x'   # subset; omit for all built-in arches
      shards: 10             # default 20

Inputs (cross.yml)

Input	Type	Default	Meaning
arches	string	''	Space-separated. Empty -> all arches in ci/arches.
shards	number	20	Test shards per arch.
strace-repository	string	''	Empty -> the calling repo (github.repository).
strace-ref	string	''	Empty -> the calling commit (github.sha).

Adding an architecture

1. Add the arch name to ci/arches.
2. Add ci/buildroot-config-<arch> (with a # CONFIG_VERSION: marker).
3. Add the per-arch QEMU/guest settings to the case "$ARCH" block in ci/lib.sh.

How it works

cross.yml (the engine, workflow_call only) resolves the arch list and strace source, then fans out a matrix calling arch.yml per arch. arch.yml builds the toolchain + strace (caching both), then runs the test suite sharded across parallel QEMU jobs.

Patches

Two patches are applied to the cross toolchain during the Buildroot build (via BR2_GLOBAL_PATCH_DIR in the arch configs that need them), fixing build-environment bugs that would otherwise cause false strace failures:

• ci/patches/gcc/ -- m68k fold-mem-offsets miscompile breaking sendfile/splice.
• ci/patches/elfutils/ -- mips64el MIPS unwinding bug breaking strace -k/-kk.

Running locally

The ci/ scripts are plain POSIX shell:

export STRACE_SRC=$PWD/strace BUILDROOT_SRC=$PWD/buildroot OUTPUT_BASE=$PWD/output
./ci/build-buildroot s390x                       # toolchain, kernel, rootfs (slow)
STRACE_PATCHES=ci/strace-patches ./ci/build-strace s390x   # cross-compile (patches optional)
./ci/run-qemu        s390x                       # boot under QEMU, run make check

License

GPL-2.0-or-later. See LICENSE.