bash: eval: line 4: syntax error: unexpected end of file

[spare kayak]

Hi, while using latest warp and bash-5.2.37 on Mac from homebrew, each time I press ENTER, I get this error message. I've narrowed it down to Warp, as it does not appear with iTerm2 with the same shell. Probably linked to the PROMPT_COMMAND variable;

echo $PROMPT_COMMAND
__bp_precmd_invoke_cmd

Any help or tips really appreciated

[supple wolf]

Hi @spare kayak. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:

---

Based on the information in the knowledge sources, there are known issues with how Warp handles the PROMPT_COMMAND variable in Bash, especially with newer Bash versions (like 5.1+ from Homebrew). Warp previously had a bug where it would attempt to "flatten" a PROMPT_COMMAND array into a string using semicolons, which could cause syntax errors if any element ended with a semicolon or ampersand. This could result in errors similar to what you're seeing, especially if you use tools like bash-preexec or have custom prompt hooks set up in your Bash configuration.

The error message you’re seeing (bash: eval: line 4: syntax error: unexpected end of file) is consistent with these issues. The problem is specific to Warp and does not appear in other terminals like iTerm2, as you observed.

What you can try:

1. Update Warp: This specific bug with PROMPT_COMMAND flattening was fixed in a recent Warp release. Please ensure you are running the latest version of Warp, as the fix should resolve this issue for most users. Users have confirmed that the problem is resolved in the latest version of Warp In Bash, PROMPT_COMMAND array causes a syntax error when an element ends with ;, &, etc..

2. Check PROMPT_COMMAND: If you are still seeing the error, try temporarily unsetting PROMPT_COMMAND in your .bashrc or .bash_profile for Warp sessions to see if the error goes away. You can do this conditionally for Warp:

   if [[ $TERM_PROGRAM == "WarpTerminal" ]]; then
     unset PROMPT_COMMAND
   fi
   

3. Check for Incompatible Plugins: Some plugins or prompt tools (like bash-preexec, bash-it, or others) may still cause issues. Review your Bash configuration for any such tools and see if disabling them for Warp resolves the problem. There is a list of known incompatible tools you can reference.

If after updating Warp and trying the above steps you still encounter the error, it may be a new or related bug. In that case, consider opening a new issue on the Warp GitHub with your configuration details.

Summary:
This is a known Warp-specific issue with Bash and PROMPT_COMMAND, especially with newer Bash versions and certain plugins. Update Warp to the latest version and review your prompt-related configuration as described above. If the problem persists, further investigation may be needed, but the latest release should resolve it for most users In Bash, PROMPT_COMMAND array causes a syntax error when an element ends with ;, &, etc..

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

@spare kayak Kapa.ai is still learning and improving, please let me know how I did by reacting below.

[spare kayak]

ok going back to iTerm2 for now on, as latest Warp release does not fix the issue and no time to investigate. Feel free to contact me if you need feedback from me.

[normal scaffold]

Question, why are you using bash then using preexec to get ZSH functionality? Why not keep the default ZSH that Mac is built with?

Are you using this for anything special? Some context around your bash config and how you have this setup would allow you to get better support.