Skip the verbose test rerun after a timeout (closes #61)

A hung test used the 90-second backstop twice, because the verbose
rerun waited for the same hang. The Go recipe now looks in the first
run's output for what Go prints for a hang, and exits 1 with no rerun.
Any other failure still reruns with -v.

The Python make test example takes the same timeout wrapper as its
Dockerfile example. The 60 and 90 second rule and the 5-minute rule say
a hung package uses the backstop once.

Model: opus-5-5

TODO.md

@@ -21,6 +21,15 @@ fmt-check, and commit.
 
 # Completed Steps
 
+- 2026-11-03: A first test run that timed out now gets no verbose rerun
+  (https://git.eeqj.de/sneak/prompts/issues/61), on sneak's approval at
+  https://git.eeqj.de/sneak/prompts/issues/61#issuecomment-165195. The Go recipe
+  in `REPO_POLICIES.md` looks in the first run's output for
+  `panic: test timed out` or `*** Test killed`, and exits 1 when either is
+  there. The Python `make test` example takes the same `timeout 90 sh -c`
+  wrapper as its `Dockerfile` example. The 60 and 90 second rule and the
+  5-minute rule now say a hung package uses the backstop once. Consuming
+  repositories pick this up on their next re-vendor.
 - 2026-10-27: Added `prompts/API_POLICIES.md`
   (https://git.eeqj.de/sneak/prompts/issues/137). It holds sneak's rule from
   https://git.eeqj.de/sneak/routewatch/issues/199 that a value in an API

prompts/REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-10-27
+last_modified: 2026-11-03
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -233,6 +233,7 @@ style conventions are in separate documents:
     # Test phase. -race needs cgo and so a C compiler, which the Debian Go
     # image ships and the alpine one does not. -count=1 because the mounted
     # cache also holds test results, which go test would otherwise replay.
+    # A first run that timed out gets no rerun: its output has the stacks.
     # golang:1.x, YYYY-MM-DD
     FROM golang@sha256:... AS test
     WORKDIR /src
@@ -241,9 +242,16 @@ style conventions are in separate documents:
     ARG CACHEBUST
     COPY . .
     RUN --mount=type=cache,target=/root/.cache/go-build \
-        go test -count=1 -timeout 90s -race -cover ./... || \
-        { echo "--- Rerunning with -v for details ---"; \
-          go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+        output=$(go test -count=1 -timeout 90s -race -cover ./... 2>&1); \
+        status=$?; \
+        printf '%s\n' "$output"; \
+        test "$status" -eq 0 && exit 0; \
+        case "$output" in \
+            *"panic: test timed out"*|*"*** Test killed"*) exit 1 ;; \
+        esac; \
+        echo "--- Rerunning with -v for details ---"; \
+        go test -count=1 -timeout 90s -race -v ./...; \
+        exit 1
 
     # Build stage. Nothing is wanted from either phase above; the copies
     # are what make BuildKit build them first, so nothing after them can
@@ -413,7 +421,8 @@ style conventions are in separate documents:
     `pipenv install --dev --deploy`:
 
     ```dockerfile
-    # Test phase. The 90-second timeout covers both pytest runs.
+    # Test phase. Both pytest runs share one 90-second timeout, so a hang
+    # uses it once and gets no rerun.
     # python:3.x-slim, YYYY-MM-DD
     FROM python@sha256:... AS test
     # make and git are base tools that script/bootstrap installs when they
@@ -484,20 +493,25 @@ style conventions are in separate documents:
   improvement bug against that repo. Add a 90-second timeout to the test
   invocation (`go test -timeout 90s`). The backstop deliberately sits above the
   hard cap so that it catches a genuinely hung test rather than a merely slow
-  one.
+  one. A hung package uses the backstop once, because a first run that timed out
+  gets no rerun. `-timeout` applies to each package, so several hung packages
+  can each use it.
 
 - **The test command should use the conditional verbose rerun pattern.** Run
   tests without `-v` (verbose) first. If tests fail, automatically rerun with
   `-v` to show full output. This keeps CI logs and `docker build` output clean
   on success (just package/suite summaries) while providing full diagnostic
-  detail on failure (every test case, every assertion). The command lives in the
-  `test` phase of the `Dockerfile`, since `script/test` builds that phase; the
-  Makefile form below is the same pattern for any repo-local invocation:
+  detail on failure (every test case, every assertion). A first run that timed
+  out gets no rerun, because the rerun would only wait for the same hang. The
+  command lives in the `test` phase of the `Dockerfile`, since `script/test`
+  builds that phase; the Makefile form below is the same pattern for any
+  repo-local invocation:
 
     ```makefile
     test:
     	@<test-command> || \
-    		{ echo "--- Rerunning with -v for details ---"; \
+    		{ <exit 1 if that run timed out>; \
+    		  echo "--- Rerunning with -v for details ---"; \
     		  <test-command-with-v>; exit 1; }
     ```
 
@@ -505,11 +519,29 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@go test -count=1 -timeout 90s -race -cover ./... || \
-    		{ echo "--- Rerunning with -v for details ---"; \
-    		  go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+    	@output=$$(go test -count=1 -timeout 90s -race -cover ./... 2>&1); \
+    		status=$$?; \
+    		printf '%s\n' "$$output"; \
+    		test "$$status" -eq 0 && exit 0; \
+    		case "$$output" in \
+    			*"panic: test timed out"*|*"*** Test killed"*) exit 1 ;; \
+    		esac; \
+    		echo "--- Rerunning with -v for details ---"; \
+    		go test -count=1 -timeout 90s -race -v ./...; \
+    		exit 1
     ```
 
+    The first run's output is kept so that the recipe can look in it for what Go
+    prints for a hang:
+    - `panic: test timed out` means the test's own timer fired.
+    - `*** Test killed` means `go test` stopped a test that ignored that timer,
+      about a minute later.
+
+    Go prints the goroutine stacks with either line, as long as the test can
+    still respond. A rerun would only wait for the same hang, so the recipe
+    exits 1. Any other failure reruns with `-v`. The kept output prints when the
+    first run ends, not while it runs.
+
     `-count=1` is required on both invocations: it defeats Go's test _result_
     cache, so neither run can report a stored pass in place of running the
     tests. It leaves the build cache alone, so it costs the runtime of the suite
@@ -528,17 +560,22 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@python -m pytest || \
-    		{ echo "--- Rerunning with -v for details ---"; \
-    		  python -m pytest -v; exit 1; }
+    	@timeout 90 sh -c 'python -m pytest || { \
+    		echo "--- Rerunning with -v for details ---"; \
+    		python -m pytest -v; exit 1; }'
     ```
 
+    Both pytest runs share that one 90-second timeout, as in the `Dockerfile`
+    example above, so a hang uses it once and gets no rerun.
+
     The `exit 1` ensures the target always fails after a rerun — the first run
     already proved the tests are broken, so the build must not pass even if a
     flaky test happens to succeed on the second attempt. The rerun exists solely
     for diagnostic output.
 
-- Docker builds must complete in under 5 minutes.
+- Docker builds must complete in under 5 minutes. A hung package uses the
+  90-second test backstop once, because a first run that timed out gets no
+  rerun.
 
 - `make check` must not modify any files in the repo. Tests may use temporary
   directories.