I similarly get this warning everywhere.
PHP Warning: mime_magic: type regex BEGIN[[:space:]]*[{]
application/x-awk invalid in Unknown on line 0
Commenting out the appropriate line in /usr/share/file/magic.mime fixes
it. The line has the comment:
# update to distinguish from *.vcf files by Joerg Jenderek: joerg dot
jenderek at web dot de
0 regex BEGIN[[:space:]]*[{] application/x-awk