in reply to Wanted: Error Documentation

In case you haven't spotted it yet, your actual problem is that you have used qw instead of m or qr to quote the regex.

$ perl -e 'print "hello" =~ qw{foo bar}' Too many arguments for regexp internal reset at -e line 1, at EOF Execution of -e aborted due to compilation errors.

(You're literally passing too many arguments to the regex matcher, i.e. a list of strings rather than the single regex that it expects.)