Order of add_dependency is important, mail-types must come before fog.

if s.add_dependency "mime-types", "~> 1.16" is specified below fog, gem considers fog first and its requirement on mime-types >= 0 and pulls in mime-types 2.0.  I gave gem too much credit for calculating dependency ordering, it does _not_ do that at all.

Apologies for prematurely pushing last fix jedi4ever, this one builds :)