Another approach is to use a full path to the script, so the latter will be used as a key in %INC:

require "/home/httpd/perl/project/MyConfig.pm";

With this solution, we solve both problems but lose some portability. Every time a project moves in the filesystem, the path must be adjusted. This makes it impossible to use such code under version control in multiple-developer environments, since each developer might want to place the code in a different absolute directory.