Problems with git commit autosigning on mac

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If you’ve enabled GPG signing for Git commits on macOS, you might occasionally encounter this frustrating error message:

❯ git commit -m 'Test'
error: gpg failed to sign the data
fatal: failed to write commit object

This happens when the GPG agent gets stuck or isn’t properly configured. Here’s how to fix it.

Quik fix

If you need a quick solution, you can restart the GPG agent using the following command:

pkill -9 gpg-agent && export GPG_TTY=$(tty)

This will kill the stuck GPG agent process and set the GPG_TTY environment variable to the current terminal. After running this command, retry your Git operation.

Permanent Fix

To avoid encountering this issue repeatedly, you can configure your shell to automatically set the GPG_TTY environment variable. Follow these steps:

  1. Open your shell configuration file. This could be ~/.bashrc, ~/.zshrc, or ~/.bash_profile, depending on your shell.
  2. Add the following lines:
    GPG_TTY=$(tty)
    export GPG_TTY
    
  3. Save the file and reload your shell configuration. You can do this by running:
    source ~/.bashrc  # Replace with your shell configuration file
    

These steps ensure that the GPG agent always knows the correct terminal to use, preventing the error from occurring.

Bonus Tips

  1. Ensure GPG is Properly Installed and Updated, use Homebrew to install or update GPG on macOS:
    brew install gpg
    
    or
    brew upgrade gpg
    
  2. Check Your Git Configuration, verify that your Git is configured to use GPG for signing:
    git config --global user.signingkey <your-gpg-key-id>
    git config --global commit.gpgsign true
    
  3. Debugging GPG Issues, if you still face problems, increase GPG’s verbosity to diagnose the issue:
    gpg --list-keys
    GPG_TTY=$(tty) gpg --sign testfile.txt
    

With these steps, your GPG signing experience on macOS should be smooth and error-free. Happy coding!

Don’t Trust Me — Seriously

The author takes no responsibility for any mishaps, broken servers, or existential crises caused by following this information.

If you spot a mistake, have a better way of doing things, or just want to chat about tech, feel free to reach out.

Also, this isn’t an ad — unless my enthusiasm and advocacy for cool stuff count as advertising.