title: My Perl module from CPAN won't install, what do I do?
body: <p>This is a canonical question for the above problem, inspired by <a href="https://stackoverflow.com/a/27891153/58074">this answer</a> and <a href="https://stackoverflow.com/questions/30627467/why-does-installing-numberformat-on-win-64-fail">this question</a>.  Please edit and improve it.</p>
  
  <p>I'm trying to install a module from CPAN, using the CPAN/cpanm/CPANPLUS client.  However, I'm getting build or test errors when I try to install it.  What should I do?</p>