fix(test): make httpapi-exercise 500s carry their cause (TKT-372, fb 183)

[sepo-eng]

First item of TKT-372, which orders 183 first (diagnosability unblocks the rest).

The reported problem is real; its stated cause is not

An effect-mode failure gave you {"name":"UnknownError","ref":"err_xxxxxxxx"} and nothing else, anywhere. Feedback 183 pinned that on backend.ts:79's { disableLogger: true }.

I tested that before implementing it, and it is wrong. disableLogger only controls whether HttpMiddleware.logger — the per-request access log — is composed in. Building the same dying route both ways prints the middleware's Effect.logError in both arms:

ARM disableLogger=true   -> ERROR failed { ref, error, cause: "..." }   <- still logged
ARM disableLogger=false  -> ERROR failed { ref, error, cause: "..." }
                            INFO  Sent HTTP response { ... }            <- the only difference

Had I implemented the suggested fix, it would have merged looking correct and changed nothing.

The actual suppressor

packages/core/src/observability.ts builds logging as Logger.layer([...Logging.loggers()], { mergeWithExisting: false }) — it replaces the console logger — and Logging.loggers() returns the file logger alone unless OPENCODE_PRINT_LOGS === "1". The Cause was never discarded; it was written to opencode.log while the harness printed an opaque ref.

The fix

Default OPENCODE_PRINT_LOGS=1 and OPENCODE_LOG_LEVEL=ERROR in the exerciser's environment.ts, alongside the OPENCODE_DB and XDG isolation that already has to happen before the app modules load. Both are ??=, so an explicit value still wins.

Error level only, so this adds one line per defect and nothing else.

Verified against a real failure

Forcing a route to die (throw in the global.health handler):

• With the default — the failure prints the full Cause with file and line, and the logged ref=err_a8d0807b matches the ref in the 500 body, so a failure correlates to its cause:

  level=ERROR message=failed ref=err_a8d0807b error="Error: PROBE_DEFECT_MARKER: ..."
    cause="... at GlobalHttpApi.health (handlers/global.ts:75:17)"
  FAIL GET /global/health   global.health
    Error: expected 200, got 500: {"name":"UnknownError",...,"ref":"err_a8d0807b"}
  

• Control, OPENCODE_PRINT_LOGS=0 — reproduces the reported symptom exactly: the FAIL line, the opaque ref, no cause.

(First attempt at this probe patched /global/health while running the /api/health scenario, so the arm proved nothing and the route passed. Reported here because the corrected pairing is what the evidence above rests on.)

All three modes green: 237/237 pass, 0 fail each for coverage, auth, and effect.

Noise, measured rather than promised

A green effect-mode run adds exactly four ERROR lines, all from integration scenarios that deliberately assert 500:

Scenario	Logged error
v2.integration.connect.key	Key method not found: missing
v2.integration.connect.oauth	OAuth method not found: missing/missing
v2.integration.attempt.status	OAuth attempt not found: con_missing
v2.integration.attempt.complete	OAuth attempt not found: con_missing

Those four routes raise plain Errors instead of returning a typed 404, which is why they land in the defect path at all. This change makes that visible; it does not cause it, and it is out of scope here.

Not in this PR

The rest of TKT-372 (146, 147, 189, 190, and verifying whether 146/147 explain 145/151) — the ticket stages 183 first deliberately. One finding for whoever takes the next slice: feedback 146's suggested remedy is now known-harmful. It proposes per-scenario fresh memoMaps, but TKT-349 moved runtime.ts the opposite way, onto the shared production MemoMap, because a fresh Layer.makeMemoMapUnsafe() there split a process singleton in two (runtime.ts:25-32 records it first-hand). The masking concern 146 raises is still real; that particular fix for it is not available.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KbNYZHcnxRCknFmhhPHe7L

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