Full suite 178s → 96s, and a run's log 12MB → 2KB. `act/runner` was 177s of the 178s, serialised behind one docker daemon.
- Its fixtures now run in parallel, bounded by a slot count instead of `go test -parallel`, with a per-test container name prefix and a pinned `MaxParallel`.
- Fixtures asserting a job failure leaked their container and network (`AutoRemove` was at the act-CLI default), filling the daemon's address pool over time.
- Replaced sleeps used as synchronisation in the parallel-executor and cache-handler tests.
- Dropped duplicate coverage: two files re-testing `NewParallelExecutor`, a test asserting on its own semaphore, and `TestDockerActionForcePullForceRebuild`, whose config `runTest` discarded.
- `fmt-check`/`security-check` move from `make test` to a `checks` target; `security-check` no longer installs `xgo` and `gxz`.
- Test flags follow gitea: `GOTEST_FLAGS ?= -race -timeout 20m -parallel 8`, with `-cover`/`-coverprofile` left in the target. Dropped `-v`, since a failing package still prints its full output without it.
Coverage unchanged at 73.4%.
Reviewed-on: https://gitea.com/gitea/runner/pulls/1121
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>
Running the full suite under `-race` (dropping `-short`) exposed pre-existing data races in parallel matrix-job execution, fixed by not sharing mutable state across combinations:
- `containerDaemonSocket()`/`validVolumes()` derive per-job values instead of mutating shared `Config`
- `getWorkflowSecrets` builds a fresh map, `rc.steps()` clones each step, and go-git workdir access is serialized
- every write to a shared `Job`'s result/outputs runs under a per-`Job` lock, each combo interpolating outputs from a pristine snapshot (last wins, as on GitHub)
### Test suite
- capability gates (docker / network / host-tools / Linux) replace the `-short` skips, and the suite runs offline via local fixtures (the artifact flow uses an in-process loopback server, only the docker-action force-pull needs the network)
- drops redundant tests, adds a regression test for https://gitea.com/gitea/runner/issues/981 and a docker-in-docker harness (`make test-dind`)
---
This PR was written with the help of Claude Opus 4.7
Reviewed-on: https://gitea.com/gitea/runner/pulls/994
Reviewed-by: Nicolas <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>
