This showed up in the description of today’s Ubuntu update. For background, file is a Unix utility that tries to identify a file’s type by looking at its contents. Sometimes this can be tricky:
file (4.26-2ubuntu4) jaunty-proposed; urgency=low
* 220-magic-update-erlang.dpatch: Escape spaces in Erlang magic to avoid misidentifications, particularly PostScript files produced on Tuesdays (LP: #248619).
The bug report gets better – the fixed bug actually makes printing not work on Tuesdays in some setups…