Once upon a time (five years ago or so) I did Perl professionally. At first I bought into the CPAN hype -- everything's there! Any library you'll ever need has already been written and is in the CPAN! -- but after actually using it for a while, I learned that Sturgeon's Law has no exceptions. There were so many packages which were broken, uninstallable, non-functional or nearly undocumented that trying to use stuff from CPAN could end up involving more time than just writing from scratch.
When, one day, I encountered documentation for one project which listed all its dependencies, and then gave a long list of things it needed which were in CPAN but in such broken states that CPAN couldn't actually be used to install them (and an even longer list of instructions for how to manually install and work through the bugs), I started looking for something else.