Closes the bug class surfaced by Canvas E2E #2632: a workspace ends up
status='failed' with last_sample_error=NULL, and operators (or the
E2E poll loop) see the useless "Workspace failed: (no last_sample_error)"
with no triage signal.
Two pieces:
1. **bundle/importer.go markFailed** — the UPDATE was setting only
status, leaving last_sample_error NULL. Same incident class as the
silent-drop bugs in PRs #2811 + #2824, different code path.
markProvisionFailed in workspace_provision_shared.go has set the
message column for a long time; this writer drifted the convention.
Fix: include last_sample_error in the SET clause + the broadcast.
2. **AST drift gate** (db/workspace_status_failed_message_drift_test.go)
— Go AST walk that finds every db.DB.{Exec,Query,QueryRow}Context
call whose argument list binds models.StatusFailed and asserts the
SQL literal contains last_sample_error. Catches the next caller
that drifts the same convention. Verified to FAIL against the bug
shape (reverted importer.go temporarily — gate flagged the exact
line) and PASS against the fix.
Why an AST gate vs a regex: pre-fix attempt with a regex over UPDATE
statements flagged status='online' / status='hibernating' / status=
'removed' UPDATEs as false positives. Walking the AST and only
flagging calls that pass the StatusFailed constant eliminates that.
Out of scope (filed separately if needed):
- The Canvas E2E that surfaced the missing message (#2632) is now a
required check on staging via PR #2827. Once this fix lands the
next staging push should re-run #2632's failing case and produce
a meaningful last_sample_error.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>