We want to have 2 perl installs, both 5.6.1, one for development and one for testing, on the same machine (please don't suggest we use another machine; we are elsewhere but not for this development). One lives under /foobar (e.g. /foobar/bin/perl, @INC has /foobar/lib/perl5/site_perl etc. in it), the other would be /foodev.
Since foobar and foodev are the same length, I assume I can copy and patch the perl binary intelligently to change the built-in @INC path, and then just copy the lib tree, looking for occurances of foobar and patching them too (e.g. Config.pm). Are there any other gotchas? It seems like a gross hack to me too, but it's a heck of a lot faster than reinstalling perl and all of our CPAN modules.