CI's zero-warning budget is Linux-only; 2,700+ core tests are compiled but never run

Summary

The zero-warning budget and most --lib test suites are only enforced on Linux, so two classes of defect reach master with CI fully green:

1. macOS-only compiler warnings. cargo check -q on macOS master (ff6fb6359) emits 5 warnings. The budget in scripts/warning_budget.txt is 0.
2. Unrun tests that are already failing. jcode-core --lib has a test that fails on clean master on macOS and is never executed by any CI job.

These are the same shape as #651, #660, and #592, which the workflow comments already document. This issue is about the general gate rather than another instance.

Evidence 1: macOS warnings on clean master

$ git checkout ff6fb6359
$ CARGO_TERM_COLOR=never cargo check -q 2>&1 | grep -c '^warning:'
5

They are:

warning: function `is_file_controlled_debug_client` is never used
warning: function `proc_pidfdinfo` is never used
warning: constant `PROC_PIDFDVNODEPATHINFO` is never used
warning: constant `PROC_PIDFDSOCKETINFO` is never used
warning: constant `PROC_PIDFDPIPEINFO` is never used

is_file_controlled_debug_client (src/cli/dispatch.rs:24) is only consumed by arm_debug_client_parent_death_signal, which is #[cfg(target_os = "linux")]. The others are macOS proc_pidfdinfo FFI declarations in crates/jcode-core/src/stdin_detect.rs that nothing references.

CI cannot see any of these:

• .github/workflows/ci.yml — the quality job runs on ubuntu-latest only.
• The Enforce warning budget (Linux) step in build is if: runner.os == 'Linux'.

So the macOS runner builds this code and never counts its warnings.

Evidence 2: a test that is red on master and never runs

$ git checkout ff6fb6359    # clean upstream, no local patches
$ cargo test -p jcode-core --lib stdin

---- stdin_detect::stdin_detect_tests::test_own_process_not_reading_stdin stdout ----
thread '...' panicked at crates/jcode-core/src/stdin_detect_tests.rs:9:5:
assertion `left != right` failed
  left: Reading
 right: Reading

test result: FAILED. 1 passed; 1 failed

Verified in a clean git worktree of origin/master, so this is not a local artifact.

The test asserts the current process is not reading stdin. On macOS it is reported as Reading, which is the false positive tracked in #1146. The failing test is therefore an existing, checked-in reproduction of #1146 that nobody sees.

jcode-core --lib is not run by any job. The only stdin-related CI step is:

-p jcode-app-core --lib tool::bash::tests::test_stdin_forwarding

which is a different crate and a different code path.

Scale of the unrun surface

Tests that exist but are not executed by any CI job:

Crate	#[test] / #[tokio::test]
jcode-base	1,377
jcode-app-core	1,335
jcode-core	39

jcode-app-core and jcode-base are compiled via --lib --bins --no-run and then only four filtered cohorts are actually run (retention_readiness, secret_input, test_stdin_forwarding, plus the embedding cohort). jcode-tui --lib is the only broad suite that runs, and it runs serially.

Suggested direction

Two independent changes; the first is nearly free.

1. Enforce the warning budget on macOS. Drop the if: runner.os == 'Linux' condition on the warning-budget step in the build matrix job. This requires the 5 warnings above to be fixed first, otherwise the macOS leg goes red immediately.

I have that part done and tested on ianalitis:chore/macos-warning-clean (3 commits, macOS cargo check -q goes 5 warnings -> 0). Happy to open it as a PR if you want it, though I currently cannot create PRs against this repo (see note below).

2. Run the core lib suites, serially. Mirror the existing jcode-tui --lib step for the two big crates:

- name: Run core library tests (Linux only)
  if: runner.os == 'Linux'
  run: |
    python3 .github/scripts/run_with_timeout.py 900 \
      "$(rustup which cargo)" test --target ${{ matrix.target }} \
      -p jcode-app-core -p jcode-base -p jcode-core --lib -- --test-threads=1

Serial execution is required for the same reason it is on jcode-tui: shared process-global state (#592, #1141). I expect this to be red on the first run. The value is that the resulting list becomes a visible backlog rather than a silent one.

If a fully green gate is wanted immediately, this could start as a separate non-blocking job and be promoted once the list is drained.

Note

I cannot open pull requests against this repository with my current token (createPullRequest returns 404 / "does not have the correct permissions"), though issue creation works. The branch above is pushed to my fork if you would like to pull from it, or I am happy to attach the diffs here instead.

Start with .github/workflows/ci.yml, scripts/warning_budget.txt, and the existing Linux warning-budget and jcode-tui test steps. Run cargo check -q and the affected jcode-core library test on macOS, then inspect the three listed library test suites and their current CI coverage. Done means the intended warning budget and library-test coverage are enforced without masking the known failures.