It does not matter if your module uses all the dependencies as you (the developer) test because you probably have all of them installed. You probably will not notice missing PREREQ_PM on the developer side.

I got bit with this frequently until I created Test::Prereq which compiles the modules in a distribution, extracts as much dependency information as it can, and compares that with PREREQ_PM. It saved me a ton of hassles.

But then, CPANPLUS is still pretty young, and I had to work around it a bit in Test::Prereq so I didn't get back misleading bug reports from CPAN Testers. I would prefer they not use CPANPLUS until it is more mature, but that's life. Fixing distributions to support a popular but buggy distribution tool definitely sucks.

I did start quoting the module version numbers in PREREQ_PM, though ( "Foo::Bar" => "0.1" ) which seemed to ameliorate the problem for a while, but that was a couple years ago so I forget the details. I haven't bothered to check up on that.