I was getting an error when launching Audacity.
The error was:
“The system has detected that another copy of Audacity is running.”
However, Audacity wasn’t running at all. Not one process. It turned out to be just a locked file located in /var/tmp/audacity-[your-username].
All you have to do is delete the entire directory and rerun Audacity.
rm -rf /var/tmp/audacity=[your-username]/
Once deleted, Audacity starts right up with no issues.