"known to have minor test failures"

[pdl]

I got some failures running perlbrew install 5.10.1, which I thought might happen, it's pretty old.

The failure message finished as follows:

Generally, if you need to install a perl distribution known to have minor test
failures, do one of these command to avoid seeing this message

 perlbrew --notest install 5.10.1
 perlbrew --force install 5.10.1

Who is it that is doing the knowing in "known to have minor test failures"? Is there any list of versions known to have minor (or indeed major) failures and what the implications are?

I'd've thought any failure is a failure, but it sounds like some are genuinely unimportant. Is there any guide to working out when minor test failures are minor enough that it's probably ok to go ahead and install?

(By the way, perlbrew is great! Thanks to anyone who's worked on it that reads this.)