if you state a dependency on a standard perl module in DEPENDENCIES, and the dependency is not satsfied on the target platform, then CPAN::Shell will automatically try to upgrade Perl.

This is because standard perl modules have perl in their prerequisites.

This can be avoided by checking to see if a module is a standard module before attempting to install it, and bottling out with a "I'm not touching that with a 16ft barge-pole" type of error.

CC