Prior to this patch, the testsuite used your global package db, and
sometimes, the inplace package db, which led to errors if you didn't
have old-time installed globally. They looked like this:

BuildDeps/SameDepsAllRound:          Cabal result was Result {successful = False, success = Failure, outputText = "\"/home/enolan/cabal/Cabal/tests/Setup configure --user -w  /home/enolan/.nix-profile/bin/ghc\" in PackageTests/BuildDeps/SameDepsAllRound\nConfiguring SameDepsAllRound-0.1...\nSetup: At least the following dependencies are missing:\nold-time -any\n"}