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 the lines Go prints for a hang, and exits 1 with no
rerun. A failure with neither line in its output 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. The Go item in both repo
checklists now asks for this.

Model: opus-5-5

TODO.md

@@ -28,8 +28,9 @@ fmt-check, and commit.
   `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.
+  5-minute rule now say a hung package uses the backstop once. The Go item in
+  both repo checklists now asks for this, so a repository with the old recipe
+  fails it.
 - 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/EXISTING_REPO_CHECKLIST.md

@@ -1,6 +1,6 @@
 ---
 title: Existing Repo Checklist
-last_modified: 2026-10-26
+last_modified: 2026-11-03
 ---
 
 Use this checklist when beginning work in a repo that may not yet conform to our
@@ -70,8 +70,9 @@ with your task.
       (`--mount=type=cache,target=/root/.cache/go-build`), `golangci-lint run`
       also mounts golangci-lint's
       (`--mount=type=cache,target=/root/.cache/golangci-lint`), and no step
-      mounts anything else; both `go test` runs carry `-count=1`, as in the
-      canonical Go `Dockerfile` in `REPO_POLICIES.md`
+      mounts anything else; both `go test` runs carry `-count=1`; a first run
+      that timed out gets no rerun, as in the canonical Go `Dockerfile` in
+      `REPO_POLICIES.md`
 - [ ] Python: a `test` phase that installs its packages from `Pipfile.lock` does
       it above `ARG CACHEBUST`, with `COPY script/ script/`,
       `COPY Pipfile Pipfile.lock ./` and `RUN script/bootstrap`. When

prompts/NEW_REPO_CHECKLIST.md

@@ -1,6 +1,6 @@
 ---
 title: New Repo Checklist
-last_modified: 2026-10-26
+last_modified: 2026-11-03
 ---
 
 Use this checklist when creating a new repository from scratch. Follow the steps
@@ -129,8 +129,9 @@ Template files can be fetched from:
       (`--mount=type=cache,target=/root/.cache/go-build`), `golangci-lint run`
       also mounts golangci-lint's
       (`--mount=type=cache,target=/root/.cache/golangci-lint`), and no step
-      mounts anything else; both `go test` runs carry `-count=1`, as in the
-      canonical Go `Dockerfile` in `REPO_POLICIES.md`
+      mounts anything else; both `go test` runs carry `-count=1`; a first run
+      that timed out gets no rerun, as in the canonical Go `Dockerfile` in
+      `REPO_POLICIES.md`
     - Python: a `test` phase that installs its packages from `Pipfile.lock` does
       it above `ARG CACHEBUST`, with `COPY script/ script/`,
       `COPY Pipfile Pipfile.lock ./` and `RUN script/bootstrap`. When

prompts/REPO_POLICIES.md

@@ -233,7 +233,8 @@ 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.
+    # A first run that timed out gets no rerun, because a rerun would only
+    # wait for the same hang.
     # golang:1.x, YYYY-MM-DD
     FROM golang@sha256:... AS test
     WORKDIR /src
@@ -242,8 +243,8 @@ style conventions are in separate documents:
     ARG CACHEBUST
     COPY . .
     RUN --mount=type=cache,target=/root/.cache/go-build \
-        output=$(go test -count=1 -timeout 90s -race -cover ./... 2>&1); \
-        status=$?; \
+        status=0; \
+        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 \
@@ -510,8 +511,7 @@ style conventions are in separate documents:
     ```makefile
     test:
     	@<test-command> || \
-    		{ <exit 1 if that run timed out>; \
-    		  echo "--- Rerunning with -v for details ---"; \
+    		{ echo "--- Rerunning with -v for details ---"; \
     		  <test-command-with-v>; exit 1; }
     ```
 
@@ -519,8 +519,8 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@output=$$(go test -count=1 -timeout 90s -race -cover ./... 2>&1); \
-    		status=$$?; \
+    	@status=0; \
+    		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 \
@@ -539,8 +539,8 @@ style conventions are in separate documents:
 
     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.
+    exits 1. A failure with neither line in its output 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
@@ -566,7 +566,10 @@ style conventions are in separate documents:
     ```
 
     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.
+    example above, so a hang uses it once and gets no rerun. Ctrl-C does not
+    stop a running `make test`, which goes on until the tests end or the 90
+    seconds run out. On a Mac without `timeout`, the target fails until it is
+    installed.
 
     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