Why does my iTerm2 launch with an X in it's path?
You have shell integration installed and the last command executed failed:

Example:



DoesNotExist cmd does not exist, thus an error 127:




  Command status
  
  The mark on a command line will turn red if a command fails. You can right click the mark to view its return code.


Re: https://iterm2.com/shell_integration.html