With CPAN version 1.91_53 and CPAN::Reporter version 0.99_02, CPAN will now report to CPAN::Testers any failures during Makefile.PL (Build.PL) or make (Build).
Ironically, this pair now needs some good-old-fashioned manual testing. Please consider installing them and then testing some modules that you've seen fail to build on your system.
cpan> install ANDK/CPAN-1.91_53.tar.gz
cpan> install DAGOLDEN/CPAN-Reporter-0.99_02.tar.gz
cpan> reload cpan
Then test some module that fails to even make and see if the failure report made it to CPAN Testers.