Currently, the regex explicitly only allows escaped spaces in filenames.

But some tools like flake8 print the output with unescaped file names, even if the input was escaped.
Currently, there is no way to match those filenames.

example

cat foo\ bar/a.py | flake8 --stdin-display-name foo\ bar/a.py -

foo bar/a.py:1:80: E501 line too long (144 > 79 characters)

Not really sure if there is a good solution for this