I'm using EPIC with Eclipse under Windows and ran into the well known error on loading the debugger, which needs a workaround by patching one line in Cwd.pm. Of course this fix is trivial and after applying it the debugger works for me, but I would rather avoid changing Perl's core like this. I therefore tried to copy Cwd.pm in the directory .metadata\.plugins\org.epic.debug from my Eclipse workspace, changed the file only there and it worked, too. I saw in the directory and read somewher ein the net you are already using a similar approach for perl5db.pl, which is copied from the Perl directory, patched with only one statement, saved in the same directory and executed from there.
Is there any reason why you don't do the same for Windows users with Cwd.pm? From my point of view it would be a much better workaround as core Perl isn't changed at all and EPIC would work with Windows out of the box.