Though this has been already resolved but let me send it here for the next person who might fall in this trap
I got the error message "Makefile:1457: *** multiple target patterns. Stop." when I was trying to add a Makefile.PL to Bugzilla. The problem was that Bugzilla has its modules from the root directory and there is a lib/ subdirectory that is the target location of 3rd party CPAN modules installed for Bugzilla. Specifically I had a a bunch of lib/man/man3/*.3pm files. So when I tried to run perl Makefile.PL make I got the above error message. Once I removed those files the standard module installation process went well. Gabor
