cpan.rb -- avoid hangs by overriding interactive prompts with PERL_MM_USE_DEFAULT and AUTOMATED_TESTING

[tomeon]

Some CPAN modules default to requiring user input during the make/test/install process. fpm does not hand control back to the user at such prompts, causing the build process to mysteriously hang. Setting the PERL_MM_USE_DEFAULT and AUTOMATED_TESTING environment variables to 1 deals with the most common sources of such hangs.*

Although it might be preferable to allow interactive input under such circumstances, implementing that is likely to be much harder, and, in any case, if users wanted to do stuff interactively they probably wouldn't be using fpm ;).

• Confusingly, Module::Build also uses PERL_MM_USE_DEFAULT, rather than PERL_MB_USE_DEFAULT.

[jordansissel]

Hmm; this one now merge conflicts. Can you resolve that?

[tomeon]

Resolved, a mere 12 weeks later ;).