From 405b6476bb58ae4819b4b8281515cf5a4c4250ca Mon Sep 17 00:00:00 2001
From: Tom Elizaga <tom.elizaga@gmail.com>
Date: Tue, 24 Feb 2026 13:04:28 -0800
Subject: [PATCH] fix: show helpful error when running `git gtr cd`

`cd` only works through the shell function wrapper (`gtr cd`) since
subprocesses cannot change the parent shell's directory. Instead of the
generic "Unknown command" error, detect `cd` and print setup instructions
with the user's shell auto-detected.
---
 bin/git-gtr | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/bin/git-gtr b/bin/git-gtr
index 820f71e..21af41a 100755
--- a/bin/git-gtr
+++ b/bin/git-gtr
@@ -106,6 +106,14 @@ main() {
     help|--help|-h)
       cmd_help "$@"
       ;;
+    cd)
+      local _shell_name
+      _shell_name="$(basename "${SHELL:-bash}")"
+      log_error "'cd' requires shell integration (subprocesses cannot change your shell's directory)"
+      log_info "Set up with: eval \"\$(git gtr init $_shell_name)\""
+      log_info "Then use:    gtr cd [<branch>]"
+      exit 1
+      ;;
     *)
       log_error "Unknown command: $cmd"
       echo "Use 'git gtr help' for available commands"