Stop vault safety checks from reading unreadable state as empty (closes #51)

Adding a PGP unlocker checked unlockers.d for a duplicate and, when the
directory could not be read, reported no duplicate and went on. It now
stops with an error naming the directory and cause.

The same flaw guarded removing the last unlocker and removing a vault
(an unreadable secrets directory counted as no secrets) and vault
import (an unreadable pub.age counted as no long-term key). Those now
stop with an error too. `unlocker list` keeps skipping entries it
cannot read.

`vault rm` and `unlocker rm` now take the state directory lock and call
an unexported function that does the work, as `vault import` does, so
the tests can reach their checks.

Model: opus-5-5

TODO.md

@@ -25,6 +25,13 @@ Bring the repo into policy compliance in one commit:
 
 # Completed Steps
 
+- 2026-10-04: The `internal/cli` tests are back to about their time
+  before the state directory lock
+  (https://git.eeqj.de/sneak/secret/issues/80). The test that each
+  changing command waits for the lock releases it as soon as it sees the
+  command waiting there, instead of after a fixed 100 ms. The two vaults
+  with passphrase unlockers that the path and move tests start from are
+  made once and copied for each test.
 - 2026-10-04: `secret mv` rejects a move whose destination is the source
   under another name, such as `foo` for `Foo` on a case-insensitive
   filesystem (the macOS default) or a name reached through a symbolic

internal/cli/lock_test.go

@@ -2,9 +2,11 @@
 package cli
 
 import (
+	"bytes"
 	"io"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -25,11 +27,6 @@ const (
 	// once the lock is free.
 	lockWait = 10 * time.Second
 
-	// heldWait is how long a test watches a command that must wait for the
-	// lock. A command that takes no lock changes the state directory well
-	// within it.
-	heldWait = 100 * time.Millisecond
-
 	// testPassphrase protects the passphrase unlockers the tests create.
 	testPassphrase = "test-passphrase"
 
@@ -323,10 +320,28 @@ func setupEveryCommand(
 	return versions[1], unlockerID
 }
 
+// waitingForLock reports whether a goroutine is stopped in
+// vault.LockStateDir, waiting for the in-memory filesystem's lock. The
+// stack trace of such a goroutine starts with the reason it waits,
+// "[sync.Mutex.Lock]", and names LockStateDir.
+func waitingForLock() bool {
+	stacks := make([]byte, 1<<20)
+	stacks = stacks[:runtime.Stack(stacks, true)]
+
+	for goroutine := range bytes.SplitSeq(stacks, []byte("\n\n")) {
+		if bytes.Contains(goroutine, []byte("[sync.Mutex.Lock")) &&
+			bytes.Contains(goroutine, []byte("vault.LockStateDir(")) {
+			return true
+		}
+	}
+
+	return false
+}
+
 // requireWaitsForLock runs a command, given what setupEveryCommand made,
 // while holding the state directory lock. The command must neither finish
-// nor change anything while the lock is held, and must succeed once it is
+// nor change anything before it waits for the lock, and must succeed once
-// released.
+// the lock is released.
 func requireWaitsForLock(
 	t *testing.T,
 	withUnlocker bool,
@@ -355,14 +370,20 @@ func requireWaitsForLock(
 
 	go func() { done <- run(cli, olderVersion, unlockerID) }()
 
-	select {
+	timeout := time.After(lockWait)
-	case err := <-done:
+
-		t.Fatalf("finished while the lock was held, with error %v", err)
+	for !waitingForLock() {
-	case <-time.After(heldWait):
+		select {
+		case err := <-done:
+			t.Fatalf("finished while the lock was held, with error %v", err)
+		case <-timeout:
+			t.Fatal("never waited for the lock")
+		case <-time.After(time.Millisecond):
+		}
 	}
 
 	assert.Equal(t, before, stateDirModTimes(t, fs),
-		"changed the state directory while the lock was held")
+		"changed the state directory before waiting for the lock")
 
 	release()
 

internal/cli/path_traversal_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"slices"
 	"strings"
+	"sync"
 	"testing"
 
 	"git.eeqj.de/sneak/secret/internal/cli"
@@ -32,9 +33,20 @@ const (
 	missingFile = "/no/such/file"
 )
 
+// The state directory newTwoVaultFs copies, recorded by snapshotStateDir.
+// Creating a passphrase unlocker is slow by design, so the vaults are made
+// once, by the first test that needs them.
+//
+//nolint:gochecknoglobals // shared by the tests that use newTwoVaultFs
+var (
+	twoVaultsOnce sync.Once
+	twoVaults     map[string]string
+)
+
 // newTwoVaultFs returns an in-memory filesystem holding the vaults "work"
 // and "default", the current one. Each holds the secret "x" and a
 // passphrase unlocker, so both secrets.d and unlockers.d have contents.
+// Every call returns a new copy of the same vaults.
 //
 //nolint:ireturn // afero.Fs is the filesystem abstraction used throughout
 func newTwoVaultFs(t *testing.T) afero.Fs {
@@ -42,21 +54,27 @@ func newTwoVaultFs(t *testing.T) afero.Fs {
 
 	t.Setenv(secret.EnvMnemonic, testMnemonic)
 
-	fs := afero.NewMemMapFs()
+	twoVaultsOnce.Do(func() {
+		fs := afero.NewMemMapFs()
 
-	for _, name := range []string{"work", "default"} {
+		for _, name := range []string{"work", "default"} {
-		vlt, err := vault.CreateVault(fs, testStateDir, name)
+			vlt, err := vault.CreateVault(fs, testStateDir, name)
-		require.NoError(t, err)
+			require.NoError(t, err)
 
-		err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
+			err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
-		require.NoError(t, err)
+			require.NoError(t, err)
 
-		_, err = vlt.CreatePassphraseUnlocker(
+			_, err = vlt.CreatePassphraseUnlocker(
-			memguard.NewBufferFromBytes([]byte(testPassphrase)))
+				memguard.NewBufferFromBytes([]byte(testPassphrase)))
-		require.NoError(t, err)
+			require.NoError(t, err)
-	}
+		}
 
-	return fs
+		twoVaults = snapshotStateDir(t, fs)
+	})
+
+	require.NotNil(t, twoVaults, "making the vaults failed in an earlier test")
+
+	return newFsFromSnapshot(t, twoVaults)
 }
 
 // snapshotStateDir maps every file under the state directory to its