Move the canonical golangci-lint to v2.15.0 and bring back canonicalheader

v2.15.0 (released 2026-10-16, built with go1.27.0 like v2.14.0) bundles
canonicalheader with its upstream fix for non-deterministic results, the
defect behind issue 105. Linted 20 times each on a scratch package with
two planted findings beside a ResponseWriter.Header() call, v2.14.0
reported them on 8 runs and nothing on 12; v2.15.0 reported them on all
20. REPO_POLICIES.md names the new digest; .golangci.yml no longer
disables canonicalheader and is otherwise unchanged, since it verifies
against v2.15.0 as it was and default: all switches on no new linter.

.golangci.yml

@@ -3,9 +3,6 @@ version: "2"
 # Config schema uses the golangci-lint v2 layout (settings live under
 # linters.settings, not top-level linters-settings) so that the
 # thresholds below are actually applied by golangci-lint >= v2.
-#
-# This file has no formatters section, so golangci-lint run does not run
-# gofmt. A repository's script/fmt-check runs it, on the host.
 
 run:
   timeout: 5m
@@ -19,13 +16,13 @@ linters:
     - gomodguard_v2
   disable:
     # Genuinely incompatible with project patterns
-    - exhaustruct_v5   # Requires all struct fields
+    - exhaustruct      # Requires all struct fields
+    - exhaustruct_v5   # Requires all struct fields (successor to exhaustruct)
     - godot            # Requires comments to end with periods
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
     # Deprecated: the warning is attached to the old name, so it is
     # silenced by disabling that name, not by enabling the successor.
-    - exhaustruct      # Deprecated, replaced by exhaustruct_v5
     - wsl              # Deprecated, replaced by wsl_v5
     - gomodguard       # Deprecated, replaced by gomodguard_v2
   settings:
@@ -43,10 +40,7 @@ linters:
       # test-support package exists to hand a test privileges the program
       # itself must never have, so a file that is not a test must not import
       # one. Test files, and the files inside a package whose directory name
-      # ends in `test`, are where that code belongs, and are exempt. A package
-      # in a subdirectory of that directory is not exempt. `${base-path}` is
-      # the directory holding this file, so the name of the directory a
-      # repository is cloned into does not count.
+      # ends in `test`, are where that code belongs, and are exempt.
       #
       # The deny list below is the one part of this file a repository is
       # expected to extend, and the only part it may. depguard matches an
@@ -61,25 +55,24 @@ linters:
           files:
             - "$all"
             - "!$test"
-            - "!${base-path}**/*test/*"
+            - "!**/*test/**"
           deny:
             - pkg: net/http/httptest
               desc: >-
                 Test-support code belongs in test files and in packages whose
                 directory name ends in test, not in the shipped binary.
-    # Each entry names a module not to use and what to use instead. Every
-    # entry matches the module path exactly.
+    # Only decisions already recorded in the Go package defaults are
+    # listed here. Every entry matches the module path exactly.
     gomodguard_v2:
       blocked:
         - module: github.com/rs/zerolog
           recommendations:
             - log/slog
           reason: "Structured logging is stdlib log/slog."
-        # These entries cover only the github.com/go-redis/redis module paths,
-        # one entry per path, because the later releases are separate paths.
-        # A prefix match would be shorter but would also reach
-        # github.com/go-redis/redismock/v9, the test double for the successor
-        # these entries recommend.
+        # One entry per pre-fork module path, because the later releases
+        # are separate paths. A prefix match would be shorter but would
+        # also reach github.com/go-redis/redismock, the test double for
+        # the successor these entries recommend.
         - module: github.com/go-redis/redis
           recommendations:
             - github.com/redis/go-redis/v9
@@ -92,10 +85,6 @@ linters:
           recommendations:
             - github.com/redis/go-redis/v9
           reason: "Pre-fork module; use the maintained go-redis v9."
-        - module: github.com/go-redis/redis/v9
-          recommendations:
-            - github.com/redis/go-redis/v9
-          reason: "Pre-fork module; use the maintained go-redis v9."
         - module: github.com/sergi/go-diff
           recommendations:
             - github.com/aymanbagabas/go-udiff
@@ -119,4 +108,3 @@ linters:
 issues:
   max-issues-per-linter: 0
   max-same-issues: 0
-  uniq-by-line: false

TODO.md

@@ -21,37 +21,15 @@ fmt-check, and commit.
 
 # Completed Steps
 
-- 2026-11-03: The canonical golangci-lint is now v2.15.0, still built with
-  go1.27.0, so the `go` directive rule is unchanged (issue 142). Repositories
-  pick this up on their next re-vendor. Each item in the canonical
-  `.golangci.yml` was tried on a scratch module. These changed:
-    - `canonicalheader` is enabled again, because v2.15.0 fixes the random
-      misses behind issue 105.
-    - The `depguard` exemption covers only the files directly inside a directory
-      whose name ends in `test`. It used to reach every directory below that one
-      too. The name of the directory a repository is cloned into no longer
-      counts.
-    - `gomodguard_v2` also blocks `github.com/go-redis/redis/v9`, whose
-      pre-releases can still be imported under that path.
-    - `uniq-by-line` is now `false`, so a line that trips two linters reports
-      both findings.
-    - Three comments are corrected:
-        - `exhaustruct` is listed as deprecated.
-        - The test double is named `github.com/go-redis/redismock/v9`.
-        - The claim that every blocked module is in the Go package defaults is
-          gone.
-    - A comment says the file has no `formatters` section, so
-      `golangci-lint run` does not run `gofmt`.
-- 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. The Go item in
-  both repo checklists now asks for this, so a repository with the old recipe
-  fails it.
+- 2026-11-01: Moved the canonical golangci-lint to v2.15.0 (released
+  2026-10-16), still built with go1.27.0, so the `go` directive rule is
+  unchanged. The canonical `.golangci.yml` passes `golangci-lint config verify`
+  on v2.15.0, and `default: all` switches on no new linter. `canonicalheader` is
+  enabled again (issue 105): v2.15.0 carries the upstream commit "fix:
+  non-deterministic results", and on a scratch package with two planted findings
+  beside a `ResponseWriter.Header()` call, linted 20 times with each pinned
+  image, v2.14.0 reported them on 8 runs and nothing on 12, while v2.15.0
+  reported them on all 20.
 - 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: 2026-11-03
+last_modified: 2026-10-26
 ---
 
 Use this checklist when beginning work in a repo that may not yet conform to our
@@ -70,9 +70,8 @@ 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`; a first run
-      that timed out gets no rerun, as in the canonical Go `Dockerfile` in
-      `REPO_POLICIES.md`
+      mounts anything else; both `go test` runs carry `-count=1`, 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: 2026-11-03
+last_modified: 2026-10-26
 ---
 
 Use this checklist when creating a new repository from scratch. Follow the steps
@@ -129,9 +129,8 @@ 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`; a first run
-      that timed out gets no rerun, as in the canonical Go `Dockerfile` in
-      `REPO_POLICIES.md`
+      mounts anything else; both `go test` runs carry `-count=1`, 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

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-11-03
+last_modified: 2026-11-01
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -233,8 +233,6 @@ 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, because a rerun would only
-    # wait for the same hang.
     # golang:1.x, YYYY-MM-DD
     FROM golang@sha256:... AS test
     WORKDIR /src
@@ -243,16 +241,9 @@ style conventions are in separate documents:
     ARG CACHEBUST
     COPY . .
     RUN --mount=type=cache,target=/root/.cache/go-build \
-        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 \
-            *"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
+        go test -count=1 -timeout 90s -race -cover ./... || \
+        { 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
@@ -422,8 +413,7 @@ style conventions are in separate documents:
     `pipenv install --dev --deploy`:
 
     ```dockerfile
-    # Test phase. Both pytest runs share one 90-second timeout, so a hang
-    # uses it once and gets no rerun.
+    # Test phase. The 90-second timeout covers both pytest runs.
     # python:3.x-slim, YYYY-MM-DD
     FROM python@sha256:... AS test
     # make and git are base tools that script/bootstrap installs when they
@@ -494,19 +484,15 @@ 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. 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.
+  one.
 
 - **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). 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:
+  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:
 
     ```makefile
     test:
@@ -519,29 +505,11 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@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 \
-    			*"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
+    	@go test -count=1 -timeout 90s -race -cover ./... || \
+    		{ 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. 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
     tests. It leaves the build cache alone, so it costs the runtime of the suite
@@ -560,25 +528,17 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@timeout 90 sh -c 'python -m pytest || { \
-    		echo "--- Rerunning with -v for details ---"; \
-    		python -m pytest -v; exit 1; }'
+    	@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. 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
     flaky test happens to succeed on the second attempt. The rerun exists solely
     for diagnostic output.
 
-- 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.
+- Docker builds must complete in under 5 minutes.
 
 - `make check` must not modify any files in the repo. Tests may use temporary
   directories.