For the record, I'm not using perlbrew for this. Instead, I've written a perl script (using the system perl) which will build perl and all 100+ modules from source tarballs, including some patch files for cases where the module just won't compile/test clean (usually on AIX). I've got my modules in three categories, though I'm about to merge two of them: dev, test, and modules. For the distribution that will ship, I'm not going to build dev or test, but if I want to ensure they all work on each platform I can at least throw in test temporarily just to be sure. Meanwhile, I'm expecting dev boxes to use all of them. If I'm not testing, I also have in that build-perl script code to rewrite Makefile.PL/Build.PL files to remove Test::* dependencies.
The dev directory has things like Term::ReadLine::Perl (for making the perl debugger easier to use), PPI (for automated code manipulation), and Enbugger (and their prereqs not met in the modules directory). The test directory has a bunch of Test::*, but also HTTP::Daemon (for testing AnyEvent::HTTP, I think), Sub::Uplevel, and others.
I can rebuild from scratch in ~10 minutes on my Linux box. It's a bit longer on AIX. Possibly because I do most of my building on Linux on an SSD drive :-)