By default, TextMate writes errors to the standard error (STDERR) file descriptor.

Unfortunately, this means that it is not visible anywhere, unless you are running TextMate from a terminal (i.e., /path/to/TextMate.app/Contents/MacOS/TextMate, NOT just mate).

To redirect logging, set the LOG_PATH environment variable before launching TextMate. TextMate will then create TextMate.log in the LOG_PATH location.

It’s easy:

1. In a terminal, run:

   launchctl setenv LOG_PATH "$HOME/Library/Logs"
   

2. Launch TextMate.

That’s it!

If you want to verify, run this in your terminal:

tail -f ~/Library/Logs/TextMate.log

NOTE: Each time you launch TextMate, the log file is recreated. Thus, output from previous sessions is lost.