It seems that LWP::Protocol::https should be declared as a dependency (configure_requires), otherwise the build fails like this:
...
Fetching 'http://downloads.sourceforge.net/sdlpango/SDL_Pango-0.1.2.tar.gz'...
Fetch failed! HTTP response: 501 Not Implemented [501 Protocol scheme 'https' is not supported (LWP::Protocol::https not installed)] at inc/My/Builder.pm line 154.
Fetch failed! HTTP response: 599 [Internal Exception] at inc/My/Builder.pm line 154.
Checking checksum for 'download/SDL_Pango-0.1.2.tar.gz'...
...
It seems that LWP::Protocol::https should be declared as a dependency (configure_requires), otherwise the build fails like this: