Kotlin-based logic step fails on "Argument list too long" if commit message is too long

[krzema12]

See:

• https://github.com/typesafegithub/github-workflows-kt/actions/runs/13986128215/job/39160055795
• https://github.com/typesafegithub/github-workflows-kt/actions/runs/13986128214/job/39160117669

[krzema12]

Checking if it reproduces in PRs created from current main branch: #1865

[krzema12]

It works! Retrying on main: https://github.com/typesafegithub/github-workflows-kt/actions/runs/13986128215
Still fails!

[krzema12]

Fails also locally, tested with:

GHWKT_RUN_STEP='end-to-end-test:step-3' GHWKT_GITHUB_CONTEXT_JSON='{"repository":"foo", "sha": "bar", "event": {}, "event_name": "baz"}' '.github/workflows/bindings-server.main.kts'

[krzema12]

Found a clue in actions/runner#1733 - it may be because of very long contents of the env var that is being logged:

In this case, GHWKT_GITHUB_CONTEXT_JSON contains release notes for the latest Kotlin release.
I suspect if we make a dummy commit on main, with short commit message, everything will be fine.

Long-term, I think we should consider storing the GitHub context (and other contexts as well) in files.

[krzema12]

We currently put the GitHub context's JSON in an env var here:

github-workflows-kt/github-workflows-kt/src/main/kotlin/io/github/typesafegithub/workflows/dsl/JobBuilder.kt

Line 151 in 75c5a3c

env = env + mapOf("GHWKT_GITHUB_CONTEXT_JSON" to "\${{ toJSON(github) }}"),

In fact, there's a question how to do it so that it doesn't go through stdout (this likely causes the problem).