Build with the local docker daemon; add script/build (closes #44)

The Makefile exported DOCKER_HOST pointing at one private machine, so
every docker call made through make, `make lint` and `make check`
included, failed everywhere else. The line is gone: docker uses the
local daemon, or a DOCKER_HOST set in the environment.

`make build` now calls the new `script/build`, which stamps the version
and commit as the Makefile did. A VERSION set in the environment now
wins over `git describe`, not only one given as `make build VERSION=x`.
build, clean, install and docker-run are phony; install depends on
build. The vet target is removed: `script/test` runs `go vet` first.

Model: opus-5-5

README.md

@@ -139,6 +139,9 @@ matching.
 
 Moves or renames a secret within the current vault.
 - Fails if the destination already exists
+- Fails if the destination is the source under another name, such as `foo`
+  for `Foo` on a case-insensitive filesystem (the macOS default); there, to
+  change only the case of a name, move the secret to a third name first
 - Preserves all versions and metadata
 
 ### Version Management

TODO.md

@@ -32,6 +32,29 @@ Bring the repo into policy compliance in one commit:
   `git describe`) and the git commit as before. `build`, `clean`,
   `install` and `docker-run` are in `.PHONY`; `make install` depends on
   `build`. The `vet` target is gone: `script/test` runs `go vet` first.
+- 2026-10-04: `secret init` refuses when the default vault exists, and
+  `secret vault create NAME` when `NAME` does, with "vault NAME already
+  exists", before writing anything. The check is in `vault.CreateVault`,
+  which both commands call while holding the state directory lock, so two
+  creates of one vault at once cannot both pass the check. Before, either
+  command replaced the vault's metadata, passphrase unlocker and
+  `longterm.age`, so none of its secrets could be decrypted any more. Both
+  commands now ask for the unlocker passphrase before creating the vault,
+  so one stopped at that prompt leaves no vault behind.
+- 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
+  link, before changing anything, with or without `--force`, within a
+  vault and between vaults; before, `--force` removed the destination and
+  so deleted the secret. A rename that changes only letter case works on a
+  case-sensitive filesystem as before.
 - 2026-10-04: Lint runs only in docker: `script/lint` builds
   `Dockerfile.lint`, where golangci-lint is a build step rebuilt on
   every run (`--no-cache-filter`), so an unchanged tree is linted too;
@@ -71,9 +94,9 @@ Bring the repo into policy compliance in one commit:
       has one, and to a PGP, keychain or Secure Enclave unlocker added
       on the same host and day as another of its type
       (https://git.eeqj.de/sneak/secret/issues/71);
-    - from `vault create` stopped at the passphrase prompt, a new vault
-      with no unlocker that is already the current vault; from `init`
-      stopped there, the default vault with no unlocker;
+    - from `init` or `vault create` killed after the passphrase prompt
+      but before the unlocker is written, a vault with no unlocker,
+      which `vault create` has already made the current vault;
     - from an unlocker add stopped before its metadata is written, a
       directory that `unlocker list` warns about and `unlocker rm`
       cannot remove;

internal/cli/create_vault_test.go

@@ -0,0 +1,148 @@
+package cli_test
+
+import (
+	"testing"
+
+	"git.eeqj.de/sneak/secret/internal/cli"
+	"git.eeqj.de/sneak/secret/internal/secret"
+	"git.eeqj.de/sneak/secret/internal/vault"
+	"github.com/awnumar/memguard"
+	"github.com/spf13/afero"
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/require"
+)
+
+// TestCreateExistingVaultChangesNothing is a regression test for
+// https://git.eeqj.de/sneak/secret/issues/74, where running `secret init`
+// a second time, or `secret vault create` with the name of an existing
+// vault, replaced that vault's keys, so that none of its secrets could be
+// decrypted any more. Each must refuse, change nothing, and leave every
+// vault's secret readable through its passphrase unlocker.
+//
+//nolint:paralleltest // t.Setenv forbids parallel subtests
+func TestCreateExistingVaultChangesNothing(t *testing.T) {
+	t.Setenv(secret.EnvMnemonic, testMnemonic)
+	t.Setenv(secret.EnvUnlockPassphrase, testPassphrase)
+
+	// `secret init`, `secret vault create work`, `secret vault select
+	// default`, and the secret "x" in each vault. "work" is then not the
+	// current vault, which creating it again must not change.
+	fs := afero.NewMemMapFs()
+	c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
+	cmd := &cobra.Command{}
+
+	require.NoError(t, c.Init(cmd))
+	require.NoError(t, c.CreateVault(cmd, "work"))
+	require.NoError(t, c.SelectVault(cmd, "default"))
+
+	vaults, err := vault.ListVaults(fs, testStateDir)
+	require.NoError(t, err)
+	require.Len(t, vaults, 2)
+
+	for _, name := range vaults {
+		value := memguard.NewBufferFromBytes([]byte("value"))
+		err := vault.NewVault(fs, testStateDir, name).AddSecret("x", value, false)
+		require.NoError(t, err)
+	}
+
+	before := snapshotStateDir(t, fs)
+
+	tests := []struct {
+		command string
+		want    string
+		run     func(c *cli.Instance) error
+	}{
+		{
+			"init",
+			"failed to create default vault: vault default already exists",
+			func(c *cli.Instance) error { return c.Init(cmd) },
+		},
+		{
+			"vault create default",
+			"vault default already exists",
+			func(c *cli.Instance) error { return c.CreateVault(cmd, "default") },
+		},
+		{
+			"vault create work",
+			"vault work already exists",
+			func(c *cli.Instance) error { return c.CreateVault(cmd, "work") },
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.command, func(t *testing.T) {
+			fs := newFsFromSnapshot(t, before)
+
+			err := tt.run(cli.NewCLIInstanceWithStateDir(fs, testStateDir))
+
+			require.EqualError(t, err, tt.want)
+			require.Equal(t, before, snapshotStateDir(t, fs))
+		})
+	}
+
+	// Every case left the state directory exactly as recorded in before, so
+	// reading each vault's secret once from it shows that it still decrypts
+	// after each case. Without the mnemonic, reading a secret goes through
+	// the vault's passphrase unlocker, which is slow.
+	t.Setenv(secret.EnvMnemonic, "")
+
+	for _, name := range vaults {
+		value, err := vault.NewVault(fs, testStateDir, name).GetSecret("x")
+		require.NoError(t, err)
+		require.Equal(t, "value", string(value))
+	}
+}
+
+// TestStopAtPassphrasePromptLeavesNothing is a regression test for the
+// review of https://git.eeqj.de/sneak/secret/pulls/82: `secret init` or
+// `secret vault create` stopped at the passphrase prompt left a vault with
+// no unlocker, which neither command would then create again. Each must ask
+// for the passphrase before writing anything.
+//
+//nolint:paralleltest // t.Setenv forbids parallel subtests
+func TestStopAtPassphrasePromptLeavesNothing(t *testing.T) {
+	t.Setenv(secret.EnvMnemonic, testMnemonic)
+
+	// Without the passphrase in the environment, both commands prompt for
+	// it, which fails because the tests do not run in a terminal.
+	t.Setenv(secret.EnvUnlockPassphrase, "")
+
+	// An empty state directory for `secret init`, and one holding the vault
+	// "default" for `secret vault create work`.
+	empty := afero.NewMemMapFs()
+	require.NoError(t, empty.MkdirAll(testStateDir, secret.DirPerms))
+
+	withDefault := afero.NewMemMapFs()
+	_, err := vault.CreateVault(withDefault, testStateDir, "default")
+	require.NoError(t, err)
+
+	cmd := &cobra.Command{}
+
+	tests := []struct {
+		command string
+		fs      afero.Fs
+		run     func(c *cli.Instance) error
+	}{
+		{
+			"init",
+			empty,
+			func(c *cli.Instance) error { return c.Init(cmd) },
+		},
+		{
+			"vault create work",
+			withDefault,
+			func(c *cli.Instance) error { return c.CreateVault(cmd, "work") },
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.command, func(t *testing.T) {
+			before := snapshotStateDir(t, tt.fs)
+
+			err := tt.run(cli.NewCLIInstanceWithStateDir(tt.fs, testStateDir))
+
+			require.ErrorContains(t, err, "failed to read passphrase")
+			require.Equal(t, before, snapshotStateDir(t, tt.fs))
+		})
+	}
+}

internal/cli/init.go

@@ -160,6 +160,14 @@ func (cli *Instance) initialize(cmd *cobra.Command) error {
 			errInvalidMnemonicPhrase)
 	}
 
+	// Ask for the unlocker passphrase before creating the vault, so that
+	// stopping at the prompt leaves no vault without an unlocker behind
+	passphraseBuffer, err := resolvePassphrase()
+	if err != nil {
+		return err
+	}
+	defer passphraseBuffer.Destroy()
+
 	// Set mnemonic in environment for CreateVault to use
 	restoreMnemonicEnv := setMnemonicEnv(mnemonicStr)
 	defer restoreMnemonicEnv()
@@ -175,13 +183,6 @@ func (cli *Instance) initialize(cmd *cobra.Command) error {
 	// Unlock the vault with the derived long-term key
 	vlt.Unlock(ltIdentity)
 
-	// Prompt for passphrase for unlocker
-	passphraseBuffer, err := resolvePassphrase()
-	if err != nil {
-		return err
-	}
-	defer passphraseBuffer.Destroy()
-
 	// Create passphrase-protected unlocker
 	secret.Debug("Creating passphrase-protected unlocker")
 

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"
 
@@ -274,11 +271,12 @@ func stateDirModTimes(t *testing.T, fs afero.Fs) map[string]int64 {
 }
 
 // setupEveryCommand makes what each command in
-// TestChangingCommandsWaitForLock needs: the current vault "default" with
-// two versions of "test/secret", the vault "other" without a long-term key,
-// for vault import, and the file testInput. If withUnlocker is set, it also
-// gives "default" a passphrase unlocker, which is slow. It returns the older
-// version and the unlocker's ID.
+// TestChangingCommandsWaitForLock needs: the current vault "work" with two
+// versions of "test/secret", the vault "other" without a long-term key, for
+// vault import, and the file testInput. There is no vault "default", which
+// init creates. If withUnlocker is set, it also gives "work" a passphrase
+// unlocker, which is slow. It returns the older version and the unlocker's
+// ID.
 func setupEveryCommand(
 	t *testing.T, fs afero.Fs, withUnlocker bool,
 ) (string, string) {
@@ -291,7 +289,7 @@ func setupEveryCommand(
 	require.NoError(t, err)
 	require.NoError(t, fs.Remove(filepath.Join(otherDir, "pub.age")))
 
-	vlt, err := vault.CreateVault(fs, testStateDir, "default")
+	vlt, err := vault.CreateVault(fs, testStateDir, "work")
 	require.NoError(t, err)
 
 	addTestSecret(t, vlt, []byte("older"), false)
@@ -323,10 +321,28 @@ 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
-// released.
+// nor change anything before it waits for the lock, and must succeed once
+// the lock is released.
 func requireWaitsForLock(
 	t *testing.T,
 	withUnlocker bool,
@@ -355,14 +371,20 @@ func requireWaitsForLock(
 
 	go func() { done <- run(cli, olderVersion, unlockerID) }()
 
-	select {
-	case err := <-done:
-		t.Fatalf("finished while the lock was held, with error %v", err)
-	case <-time.After(heldWait):
+	timeout := time.After(lockWait)
+
+	for !waitingForLock() {
+		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/move_test.go

@@ -1,9 +1,15 @@
 package cli_test
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 
 	"git.eeqj.de/sneak/secret/internal/cli"
+	"git.eeqj.de/sneak/secret/internal/secret"
+	"git.eeqj.de/sneak/secret/internal/vault"
+	"github.com/awnumar/memguard"
+	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
 	"github.com/stretchr/testify/require"
 )
@@ -97,3 +103,127 @@ func TestMoveWithinOtherVaultKeepsCurrentVault(t *testing.T) {
 	require.Contains(t, after, workSecrets+"y/")
 	require.NotContains(t, after, workSecrets+"x/")
 }
+
+// TestMoveOntoSameSecretUnderAnotherNameIsRejected is a regression test for
+// https://git.eeqj.de/sneak/secret/issues/78: on a case-insensitive
+// filesystem "Foo" and "foo" are one secret, and `secret mv --force Foo foo`
+// removed the destination, which was the source. Symbolic links on the real
+// filesystem give one secret two names here: in "default", "y" is a link to
+// the secret "x", and the secrets.d of "other" is a link to that of
+// "default", so other:x is default:x. Each move must be rejected and leave
+// the secret and the links as they were.
+//
+//nolint:paralleltest // t.Setenv
+func TestMoveOntoSameSecretUnderAnotherNameIsRejected(t *testing.T) {
+	t.Setenv(secret.EnvMnemonic, testMnemonic)
+
+	const isSame = "is the same secret on this filesystem"
+
+	tests := []struct {
+		command      string
+		source, dest string
+		force        bool
+		wantErr      string
+	}{
+		{
+			"mv --force y x", "y", "x", true,
+			"secret 'y' cannot be moved onto itself: 'x' " + isSame,
+		},
+		{
+			"mv --force x y", "x", "y", true,
+			"secret 'x' cannot be moved onto itself: 'y' " + isSame,
+		},
+		{
+			"mv x y", "x", "y", false,
+			"secret 'x' cannot be moved onto itself: 'y' " + isSame,
+		},
+		{
+			"mv --force default:x other:x", "default:x", "other:x", true,
+			"secret 'default:x' cannot be moved onto itself: 'other:x' " +
+				isSame,
+		},
+		{
+			"mv default:x other", "default:x", "other", false,
+			"secret 'default:x' cannot be moved onto itself: 'other:x' " +
+				isSame,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.command, func(t *testing.T) {
+			fs := afero.NewOsFs()
+			stateDir := t.TempDir()
+			vaultsDir := filepath.Join(stateDir, "vaults.d")
+
+			// "default" is created last, so it is the current vault.
+			_, err := vault.CreateVault(fs, stateDir, "other")
+			require.NoError(t, err)
+
+			vlt, err := vault.CreateVault(fs, stateDir, "default")
+			require.NoError(t, err)
+
+			err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
+			require.NoError(t, err)
+
+			defaultSecrets := filepath.Join(vaultsDir, "default", "secrets.d")
+			otherSecrets := filepath.Join(vaultsDir, "other", "secrets.d")
+			link := filepath.Join(defaultSecrets, "y")
+
+			require.NoError(t, os.Symlink("x", link))
+			require.NoError(t, os.Remove(otherSecrets))
+			require.NoError(t, os.Symlink(defaultSecrets, otherSecrets))
+
+			c := cli.NewCLIInstanceWithStateDir(fs, stateDir)
+			moveErr := c.MoveSecret(&cobra.Command{}, tt.source, tt.dest, tt.force)
+
+			value, err := vlt.GetSecret("x")
+			require.NoError(t, err)
+			require.Equal(t, "value", string(value))
+
+			target, err := os.Readlink(link)
+			require.NoError(t, err)
+			require.Equal(t, "x", target)
+
+			target, err = os.Readlink(otherSecrets)
+			require.NoError(t, err)
+			require.Equal(t, defaultSecrets, target)
+
+			require.EqualError(t, moveErr, tt.wantErr)
+		})
+	}
+}
+
+// TestForcedCaseOnlyMoveOnCaseSensitiveFilesystem checks that where "Foo"
+// and "foo" are two secrets, `secret mv --force Foo foo` still replaces "foo"
+// with "Foo".
+func TestForcedCaseOnlyMoveOnCaseSensitiveFilesystem(t *testing.T) {
+	t.Setenv(secret.EnvMnemonic, testMnemonic)
+
+	fs := afero.NewOsFs()
+	stateDir := t.TempDir()
+
+	vlt, err := vault.CreateVault(fs, stateDir, "default")
+	require.NoError(t, err)
+
+	err = vlt.AddSecret("Foo", memguard.NewBufferFromBytes([]byte("upper")), false)
+	require.NoError(t, err)
+
+	_, err = os.Stat(filepath.Join(stateDir, "vaults.d", "default", "secrets.d", "foo"))
+	if err == nil {
+		t.Skip("the temporary directory is on a case-insensitive filesystem")
+	}
+
+	err = vlt.AddSecret("foo", memguard.NewBufferFromBytes([]byte("lower")), false)
+	require.NoError(t, err)
+
+	c := cli.NewCLIInstanceWithStateDir(fs, stateDir)
+	err = c.MoveSecret(&cobra.Command{}, "Foo", "foo", true)
+	require.NoError(t, err)
+
+	value, err := vlt.GetSecret("foo")
+	require.NoError(t, err)
+	require.Equal(t, "upper", string(value))
+
+	_, err = vlt.GetSecret("Foo")
+	require.ErrorIs(t, err, vault.ErrSecretNotFound)
+}

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"} {
-		vlt, err := vault.CreateVault(fs, testStateDir, name)
-		require.NoError(t, err)
+		for _, name := range []string{"work", "default"} {
+			vlt, err := vault.CreateVault(fs, testStateDir, name)
+			require.NoError(t, err)
 
-		err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
-		require.NoError(t, err)
+			err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
+			require.NoError(t, err)
 
-		_, err = vlt.CreatePassphraseUnlocker(
-			memguard.NewBufferFromBytes([]byte(testPassphrase)))
-		require.NoError(t, err)
-	}
+			_, err = vlt.CreatePassphraseUnlocker(
+				memguard.NewBufferFromBytes([]byte(testPassphrase)))
+			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

internal/cli/secrets.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"os"
 	"path/filepath"
 	"slices"
 	"strings"
@@ -890,6 +891,18 @@ func (cli *Instance) moveSecretWithinVault(
 	destEncoded := strings.ReplaceAll(dest, "/", "%")
 	destDir := filepath.Join(vaultDir, "secrets.d", destEncoded)
 
+	// Removing a destination that is the source under another name, such as
+	// "foo" for "Foo" on a case-insensitive filesystem, would delete it too.
+	same, err := cli.sameDirectory(sourceDir, destDir)
+	if err != nil {
+		return err
+	}
+
+	if same {
+		return fmt.Errorf("secret '%s' %w: '%s' is the same secret on "+
+			"this filesystem", source, errMoveOntoItself, dest)
+	}
+
 	exists, err = afero.DirExists(cli.fs, destDir)
 	if err != nil {
 		return fmt.Errorf("failed to check if destination secret exists: %w", err)
@@ -916,6 +929,31 @@ func (cli *Instance) moveSecretWithinVault(
 	return nil
 }
 
+// sameDirectory reports whether the existing directory dir and the path
+// other are one directory under two names, as secrets.d/Foo and
+// secrets.d/foo are on a case-insensitive filesystem, or a directory and a
+// symbolic link to it. Removing other to make room for dir would then delete
+// dir. It is false if other does not exist, and always false on the
+// in-memory filesystem, which has no such aliasing and whose files
+// os.SameFile does not compare.
+func (cli *Instance) sameDirectory(dir, other string) (bool, error) {
+	dirInfo, err := cli.fs.Stat(dir)
+	if err != nil {
+		return false, fmt.Errorf("failed to check %s: %w", dir, err)
+	}
+
+	otherInfo, err := cli.fs.Stat(other)
+	if errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	}
+
+	if err != nil {
+		return false, fmt.Errorf("failed to check %s: %w", other, err)
+	}
+
+	return os.SameFile(dirInfo, otherInfo), nil
+}
+
 // moveSecretCrossVault handles moving between two different vaults. Its
 // caller, MoveSecret, has already checked both secret names and that both
 // vaults exist.
@@ -940,6 +978,27 @@ func (cli *Instance) moveSecretCrossVault(
 			srcSecretName, errSecretNotFound, srcVault.Name)
 	}
 
+	// The source is removed after the copy, so a destination that is the
+	// source under another name would be lost with it.
+	destVaultDir, err := destVault.GetDirectory()
+	if err != nil {
+		return fmt.Errorf("failed to get destination vault directory: %w", err)
+	}
+
+	destStorageName := strings.ReplaceAll(destSecretName, "/", "%")
+	destSecretDir := filepath.Join(destVaultDir, "secrets.d", destStorageName)
+
+	same, err := cli.sameDirectory(srcSecretDir, destSecretDir)
+	if err != nil {
+		return err
+	}
+
+	if same {
+		return fmt.Errorf("secret '%s:%s' %w: '%s:%s' is the same secret on "+
+			"this filesystem", srcVault.Name, srcSecretName, errMoveOntoItself,
+			destVault.Name, destSecretName)
+	}
+
 	// Unlock destination vault (will fail if neither mnemonic nor unlocker available)
 	_, err = destVault.GetOrDeriveLongTermKey()
 	if err != nil {

internal/cli/vault.go

@@ -309,6 +309,14 @@ func (cli *Instance) CreateVault(cmd *cobra.Command, name string) error {
 		return errInvalidMnemonicPhrase
 	}
 
+	// Ask for the unlocker passphrase before creating the vault, so that
+	// stopping at the prompt leaves no vault without an unlocker behind
+	passphraseBuffer, err := resolvePassphrase()
+	if err != nil {
+		return err
+	}
+	defer passphraseBuffer.Destroy()
+
 	// Set mnemonic in environment for CreateVault to use
 	restoreMnemonicEnv := setMnemonicEnv(mnemonicStr)
 	defer restoreMnemonicEnv()
@@ -336,13 +344,6 @@ func (cli *Instance) CreateVault(cmd *cobra.Command, name string) error {
 	// Unlock the vault with the derived long-term key
 	vlt.Unlock(ltIdentity)
 
-	// Get or prompt for passphrase
-	passphraseBuffer, err := resolvePassphrase()
-	if err != nil {
-		return err
-	}
-	defer passphraseBuffer.Destroy()
-
 	// Create passphrase-protected unlocker
 	secret.Debug("Creating passphrase-protected unlocker")
 

internal/vault/errors.go

@@ -26,6 +26,10 @@ var (
 	// as "vault <name> does not exist".
 	ErrVaultNotFound = errors.New("does not exist")
 
+	// ErrVaultExists indicates that a vault to be created already exists.
+	// Composed as "vault <name> already exists".
+	ErrVaultExists = errors.New("already exists")
+
 	// ErrNilValueBuffer indicates a nil value buffer was supplied.
 	ErrNilValueBuffer = errors.New("value buffer is nil")
 

internal/vault/management.go

@@ -191,7 +191,11 @@ func processMnemonicForVault(
 	return derivationIndex, publicKeyHash, familyHash, nil
 }
 
-// CreateVault creates a new vault
+// CreateVault creates a new vault and selects it as the current vault. It
+// refuses a vault that already exists before writing anything: creating it
+// again would replace its keys, and its secrets could no longer be
+// decrypted. The commands that call it hold the state directory lock, so no
+// other command can create the vault between the check and the writes.
 func CreateVault(fs afero.Fs, stateDir string, name string) (*Vault, error) {
 	secret.Debug("Creating new vault", "name", name, "state_dir", stateDir)
 
@@ -207,12 +211,22 @@ func CreateVault(fs afero.Fs, stateDir string, name string) (*Vault, error) {
 
 	secret.Debug("Vault name validation passed", "vault_name", name)
 
-	// Create vault directory structure
 	vaultDir := filepath.Join(stateDir, "vaults.d", name)
+
+	exists, err := afero.DirExists(fs, vaultDir)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check if vault exists: %w", err)
+	}
+
+	if exists {
+		return nil, fmt.Errorf("vault %s %w", name, ErrVaultExists)
+	}
+
+	// Create vault directory structure
 	secret.Debug("Creating vault directory structure", "vault_dir", vaultDir)
 
 	// Create main vault directory
-	err := fs.MkdirAll(vaultDir, secret.DirPerms)
+	err = fs.MkdirAll(vaultDir, secret.DirPerms)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create vault directory: %w", err)
 	}

script/build

@@ -18,9 +18,12 @@ main() {
     fi
     commit="$(git rev-parse HEAD 2>/dev/null || echo unknown)"
     pkg=git.eeqj.de/sneak/secret/internal/cli
+    # Build the file, not the package `./cmd/secret`: a package build
+    # also stamps git status into the binary and fails where git cannot
+    # read the checkout, instead of falling back to `dev`/`unknown`.
     go build -v \
         -ldflags "-X '$pkg.Version=$version' -X '$pkg.GitCommit=$commit'" \
-        -o secret ./cmd/secret
+        -o secret cmd/secret/main.go
 }
 
 main "$@"