Cache hits replay the original log and exit status

[calvin-archastro]

Epic: Aster restores real build artifacts from a shared cache, including the GitHub Actions cache
Task: Cache hits replay the original log and exit status

Local git hooks skipped: pre-push on the submission push and the publish push. CI is the gate for what those hooks check.

Problem and author intent

A cache hit restored outputs but did not replay the stored target log or the recorded duration. The hit result used an empty output/log, duration_ms: 0, and a hardcoded exit code of 0. JSON then treated cached results like skips and dropped exit_code to None, so CI logs for cached targets stayed silent and status fields did not match the manifest.

Intent: on a hit, print Manifest.log through the same captured-output path live targets use, mark the status line (cached), and report the stored exit code and duration. --no-replay suppresses only the printed log.

What changed

Before, check_cache returned (cache_hit, hash). A hit built an ExecutionResult with empty output, zero duration, and Some(0), then called mark_cached with only the address. build_execution_output set exit_code to None when cached was true.

After, lookup is CacheLookup::Hit { manifest, log } or Miss(hash). The log blob is loaded before restore. A missing or unreadable blob, or a restore failure, warns and is a miss so the target runs instead of replaying nothing. A manifest with no log digest is still a hit with an empty log. cached_result fills output and log from the blob (from_utf8_lossy), duration_ms from manifest.duration_ms, and exit_code from manifest.exit_code. Unless the mode is JSON or --no-replay is set, that log is printed on the same channel as aster logs / ExecutionResult.output. ProgressDisplay::mark_cached then prints a (cached) suffix (CI and verbose include PASS and duration; normal mode prints the address and suffix). JSON keeps the log on the result and does not print it. Skips still use exit_code: None; cache hits no longer do. Failures are still not cached, so the stored code is expected to be 0.

Global --no-replay (default off) is threaded through the run, affected, and heterogeneous executors via Executor::with_no_replay. It suppresses printing only; cached, exit code, and duration stay on the result.

Scope

Seven paths, 24 hunks, +305/−42: .github/workflows/ci.yml, src/cli/commands.rs, src/cli/output.rs, src/executor/runner.rs, src/main.rs, src/ui/progress.rs, tests/cache_artifacts.rs. Those patch hunks are fully included (omitted_hunks: 0, omitted_paths: 0). No hasher or remote-cache backend changes are in this revision.

Risk assessment

Author grade: low. Most of the change is output and status reporting. Hit eligibility is slightly stricter: a matching manifest whose log blob cannot be read is no longer a hit. Non-UTF-8 logs can be altered by lossy UTF-8 conversion when printed or stored on output.

User impact

A cache hit on captured aster run / target execution reprints the stored log and shows (cached), with stored duration in CI and verbose progress. aster run --json results include cached: true, the stored exit_code, duration_ms, and the log in output, without printing the log to stderr. --no-replay hides the replayed log only. Callers that treated a cached exit_code as absent will now see the stored code.

Testing

Canonical test added in source: tests/cache_artifacts.rs cache_hit_replays_stored_log_and_exit_status. It runs //app:build (echo hello, cache enabled), checks aster logs stored hello, then asserts a second run replays hello and (cached); --json reports cached: true, exit_code 0, a duration_ms, and output containing hello without hello on stderr; --no-replay omits hello but still marks (cached); --json --no-replay still reports cached, exit code, and duration. The workflow diff adds --test cache_artifacts. The task states this is the macOS job, and that Ubuntu already runs cargo test --locked --workspace --all-targets --all-features.

Advisory pipeline outcomes: format, lint, and test each reported succeeded with exit code 0. Check excerpts are truncated and do not name cache_hit_replays_stored_log_and_exit_status, so this review cannot confirm that function from the CI log. Patch text is not proof the test passed. diagnostics.truncated is true; the pipeline log is not complete evidence.

Follow-ups and known issues

Streaming targets (execute_streaming) do not consult the cache. Replay covers captured run/target execution only. aster watch uses a quiet executor and does not print target logs. Cached results still set tests: None.

[calvin-archastro]

ArchDev is watching this pull request. State: watching (cycle 3 of 3 for head 911ff4f).

when	trigger	decision	result
2026-10-18T12:19:06.832Z	failed ci	enqueue job_ea5ebf1ff5555b2b17565a78	published f045896
2026-10-19T02:21:40.611Z	merge conflict	enqueue job_a6559e65346915581056167c	published 911ff4f
2026-10-19T02:37:19.462Z	verify head	enqueue job_402cd8e758668ec054c988b2	no change

Paused by the no-autofix label or a draft; never resolves reviewer threads. Jobs: job_ea5ebf1ff5555b2b17565a78, job_a6559e65346915581056167c, job_402cd8e758668ec054c988b2.