Saved By Pinto
That title may remind you of a certain song by The Fixx.
Last week a new version of CPAN::Meta was shipped to CPAN. Unfortunately, it caused a test to fail in Module::Build. In turn, that set off a whole chain of downstream failures in hundreds of distributions that depend on Module::Build.
So if you were building up a complete application stack last week (like on Stackato or Heroku) and you were pulling the latest dependencies from CPAN, you were hosed. This sort of thing happens all the time, and when it bites you, it will be at the worst possible time.
Pinto also uses Module::Build. But those who were building it with the installer at http://getpinto.stratopan.com were completely insulated from the failure. This is because the installer pulls dependencies from a private repository. Unlike the public CPAN, that repository is stable and only changes when I decide to upgrade or add a dependency.
Fortunately, the problem with CPAN::Meta was short-lived. Dave Golden had released a fixed version only 23 hours later. But I think this perfectly demonstrates why you should lock down your dependencies with a tool like Carton or Pinto.