Race with Python diagnostics and file saving
Submitted by Alexandre Franke
Open a file that does not comply with PEP-8, go to a line that shows a light bulb, quickly fix the (e.g. spacing around operator) issue and save. All lightbulbs disappear from the gutter, a new one appears at the top of the file and the tooltip claims the there is no such file 'something/something/buffer.py'.
The only way to get back to the list of lightbulbs to continue fixing your code is to close and reopen the file.