Keep Go's build cache in check builds: re-vendor sneak/prompts e3f79c4 (closes #129)

The vendored files are copies from sneak/prompts e3f79c4, with this
repository's own entries kept. The script/ builds pass a new CACHEBUST
value instead of --no-cache, which emptied Go's build cache mount, so
every make test compiled the standard library and every dependency with
-race. Every Dockerfile stage declares ARG CACHEBUST first, so every RUN
step still reruns on an unchanged tree. The steps that compile mount
Go's build cache, and both go test runs keep -count=1. The lint and test
builds write no image. script/bootstrap, script/fmt and script/fmt-check
are the canonical files plus this repository's Go steps.

Model: opus-5-5

TODO.md

@@ -29,6 +29,15 @@ https://git.eeqj.de/sneak/secret/milestone/12
   no image. The CI workflow cancels a branch's older run, stops after 20
   minutes, fetches the tags and leaves no token behind. `script/bootstrap` uses
   the installed node only when its major version is the pinned one.
+- 2026-10-15: `make test` no longer fails on some runs in `internal/cli`
+  (https://git.eeqj.de/sneak/secret/issues/192). `cli.Entry()` set `time.Local`
+  to UTC and ended by wiping every memguard buffer, and a test ran it in the
+  same process as the other tests. A timer left by an earlier test could read
+  `time.Local` as it changed, which the race detector reported, and the wipe
+  could destroy a buffer still in use, the likeliest cause of a crash of the
+  test process on another run. `main()` in `cmd/secret` now sets `time.Local`
+  before it calls `cli.Entry()`, and that test runs `cli.Entry()` in a process
+  of its own.
 - 2026-10-15: `secret mv` from one vault to another unlocks both vaults before
   it takes the state directory lock
   (https://git.eeqj.de/sneak/secret/issues/189). It unlocked them while holding

cmd/secret/main.go

@@ -3,10 +3,16 @@ package main
 
 import (
 	"os"
+	"time"
 
 	"sneak.berlin/go/secret/internal/cli"
 )
 
 func main() {
+	// Every time secret prints or writes is in UTC, whatever TZ or the
+	// system's time zone is set to. It is set here, before cli.Entry starts
+	// any goroutine that could read time.Local while it changes.
+	time.Local = time.UTC //nolint:gosmopolitan // this makes local time UTC
+
 	os.Exit(cli.Entry())
 }

internal/cli/entry_test.go

@@ -3,6 +3,7 @@ package cli_test
 import (
 	"bufio"
 	"context"
+	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -16,29 +17,67 @@ import (
 	"sneak.berlin/go/secret/internal/secret"
 )
 
-// Entry must return its exit code rather than exit, so that its deferred
-// memguard purge runs on the success and the error path alike.
-//
-//nolint:paralleltest // sets os.Args, and Entry wipes every buffer in the process
-func TestEntryWipesBuffersAndReturnsExitCode(t *testing.T) {
-	savedArgs := os.Args
+const (
+	// envRunEntry, when set, makes this test binary run cli.Entry with its
+	// own arguments and exit, instead of running the tests.
+	envRunEntry = "SECRET_TEST_RUN_ENTRY"
 
-	t.Cleanup(func() { os.Args = savedArgs })
+	// bufferWiped is what the test binary prints, run with envRunEntry set,
+	// when cli.Entry wiped the buffer made before it ran.
+	bufferWiped = "Entry wiped the buffer made before it ran"
+)
+
+// With envRunEntry set, the test binary makes a buffer, runs cli.Entry,
+// says whether the buffer is wiped, and exits with Entry's exit code. This
+// is done in init, not in a test, so that TestMain does not run in that
+// process: it would build the secret binary again, and remove it at the end,
+// while the other tests run it.
+//
+//nolint:gochecknoinits // must run before TestMain, as above
+func init() {
+	if os.Getenv(envRunEntry) == "" {
+		return
+	}
+
+	buf := memguard.NewBufferFromBytes([]byte("key material"))
+	code := cli.Entry()
+
+	if !buf.IsAlive() {
+		fmt.Fprintln(os.Stderr, bufferWiped)
+	}
+
+	os.Exit(code)
+}
+
+// Entry must return its exit code rather than exit, so that its deferred
+// memguard purge runs on the success and the error path alike. Entry wipes
+// every memguard buffer in the process, including those other tests are
+// using, so it runs in a process of its own: this test binary, run again
+// with envRunEntry set.
+func TestEntryWipesBuffersAndReturnsExitCode(t *testing.T) {
+	t.Parallel()
 
 	tests := []struct {
 		args     []string
 		exitCode int
 	}{
-		{args: []string{"secret", "--help"}, exitCode: 0},
-		{args: []string{"secret", "no-such-command"}, exitCode: 1},
+		{args: []string{"--help"}, exitCode: 0},
+		{args: []string{"no-such-command"}, exitCode: 1},
 	}
 
 	for _, tt := range tests {
-		buf := memguard.NewBufferFromBytes([]byte("key material"))
-		os.Args = tt.args
+		//nolint:gosec // G204: test runs its own test binary
+		cmd := exec.CommandContext(t.Context(), os.Args[0], tt.args...)
 
-		assert.Equal(t, tt.exitCode, cli.Entry(), "exit code for %v", tt.args)
-		assert.False(t, buf.IsAlive(), "Entry left a buffer unwiped for %v", tt.args)
+		cmd.Env = append(os.Environ(), envRunEntry+"=1")
+
+		output, err := cmd.CombinedOutput()
+		require.NotNil(t, cmd.ProcessState, "%v did not run: %v", tt.args, err)
+
+		assert.Equal(t, tt.exitCode, cmd.ProcessState.ExitCode(),
+			"exit code for %v: %s", tt.args, output)
+		assert.Contains(t, string(output), bufferWiped,
+			"Entry left a buffer unwiped for %v", tt.args)
 	}
 }
 

internal/cli/root.go

@@ -2,7 +2,6 @@ package cli
 
 import (
 	"os"
-	"time"
 
 	"github.com/awnumar/memguard"
 	"github.com/spf13/cobra"
@@ -15,10 +14,6 @@ import (
 // every memguard buffer before it returns, so the caller must do nothing
 // but exit with the code.
 func Entry() int {
-	// Every time secret prints or writes is in UTC, whatever TZ or the
-	// system's time zone is set to.
-	time.Local = time.UTC //nolint:gosmopolitan // this makes local time UTC
-
 	raiseLockedMemoryLimit()
 
 	// On SIGINT or SIGTERM memguard runs this function, wipes every buffer