pkg_resources.Requirement's constructor calls save_name() on the
project_name member which converts underscores to hyphens. Thus use
Requirement.unsafe_name (the pristine name) instead.
Coverage remained the same when pulling 6403d5145f1ad7b3705a624b614900eace5433eb on saschpe:master-underscores into 7b0cc239db30581809e081071b6945d63980173c on davidfischer:master.
pkg_resources.Requirement's constructor calls save_name() on the project_name member which converts underscores to hyphens. Thus use Requirement.unsafe_name (the pristine name) instead.