cmd/tailscale/cli: prepend "tailscale" to usage errors

Updates #11626

Signed-off-by: Paul Scott <paul@tailscale.com>

cmd/tailscale/cli/debug.go

@@ -842,7 +842,7 @@ var debugComponentLogsArgs struct {
 
 func runDebugComponentLogs(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: debug component-logs [" + strings.Join(ipn.DebuggableComponents, "|") + "]")
+		return errors.New("usage: tailscale debug component-logs [" + strings.Join(ipn.DebuggableComponents, "|") + "]")
 	}
 	component := args[0]
 	dur := debugComponentLogsArgs.forDur
@@ -865,7 +865,7 @@ var devStoreSetArgs struct {
 
 func runDevStoreSet(ctx context.Context, args []string) error {
 	if len(args) != 2 {
-		return errors.New("usage: dev-store-set --danger <key> <value>")
+		return errors.New("usage: tailscale debug dev-store-set --danger <key> <value>")
 	}
 	if !devStoreSetArgs.danger {
 		return errors.New("this command is dangerous; use --danger to proceed")
@@ -883,7 +883,7 @@ func runDevStoreSet(ctx context.Context, args []string) error {
 
 func runDebugDERP(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: debug derp <region>")
+		return errors.New("usage: tailscale debug derp <region>")
 	}
 	st, err := localClient.DebugDERPRegion(ctx, args[0])
 	if err != nil {

cmd/tailscale/cli/file.go

@@ -554,7 +554,7 @@ func runFileGetOneBatch(ctx context.Context, dir string) []error {
 
 func runFileGet(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: file get <target-directory>")
+		return errors.New("usage: tailscale file get <target-directory>")
 	}
 	log.SetFlags(0)
 

cmd/tailscale/cli/id-token.go

@@ -19,7 +19,7 @@ var idTokenCmd = &ffcli.Command{
 
 func runIDToken(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: id-token <aud>")
+		return errors.New("usage: tailscale id-token <aud>")
 	}
 
 	tr, err := localClient.IDToken(ctx, args[0])

cmd/tailscale/cli/nc.go

@@ -33,7 +33,7 @@ func runNC(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 2 {
-		return errors.New("usage: nc <hostname-or-IP> <port>")
+		return errors.New("usage: tailscale nc <hostname-or-IP> <port>")
 	}
 
 	hostOrIP, portStr := args[0], args[1]

cmd/tailscale/cli/network-lock.go

@@ -461,7 +461,7 @@ func runNetworkLockSign(ctx context.Context, args []string) error {
 	)
 
 	if len(args) == 0 || len(args) > 2 {
-		return errors.New("usage: lock sign <node-key> [<rotation-key>]")
+		return errors.New("usage: tailscale lock sign <node-key> [<rotation-key>]")
 	}
 	if err := nodeKey.UnmarshalText([]byte(args[0])); err != nil {
 		return fmt.Errorf("decoding node-key: %w", err)
@@ -508,7 +508,7 @@ func runNetworkLockDisable(ctx context.Context, args []string) error {
 		return err
 	}
 	if len(secrets) != 1 {
-		return errors.New("usage: lock disable <disablement-secret>")
+		return errors.New("usage: tailscale lock disable <disablement-secret>")
 	}
 	return localClient.NetworkLockDisable(ctx, secrets[0])
 }
@@ -545,7 +545,7 @@ var nlDisablementKDFCmd = &ffcli.Command{
 
 func runNetworkLockDisablementKDF(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: lock disablement-kdf <hex-encoded-disablement-secret>")
+		return errors.New("usage: tailscale lock disablement-kdf <hex-encoded-disablement-secret>")
 	}
 	secret, err := hex.DecodeString(args[0])
 	if err != nil {

cmd/tailscale/cli/ping.go

@@ -95,7 +95,7 @@ func runPing(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 1 || args[0] == "" {
-		return errors.New("usage: ping <hostname-or-IP>")
+		return errors.New("usage: tailscale ping <hostname-or-IP>")
 	}
 	var ip string
 

cmd/tailscale/cli/ssh.go

@@ -52,7 +52,7 @@ func runSSH(ctx context.Context, args []string) error {
 		return errors.New("The 'tailscale ssh' subcommand is not available on macOS builds distributed through the App Store or TestFlight.\nInstall the Standalone variant of Tailscale (download it from https://pkgs.tailscale.com), or use the regular 'ssh' client instead.")
 	}
 	if len(args) == 0 {
-		return errors.New("usage: ssh [user@]<host>")
+		return errors.New("usage: tailscale ssh [user@]<host>")
 	}
 	arg, argRest := args[0], args[1:]
 	username, host, ok := strings.Cut(arg, "@")