Comment 3 for bug 1418636

In utopic, /usr/share/man/man1/gem.1.gz points to gem2.1.1.gz, and comes from the ruby package.

Note that in trusty, /usr/share/man/man1/gem.1.gz pointed to gem1.9.1.1.gz (also from the ruby package), and gem1.9.1.1.gz comes from the ruby1.9.1 package. Looks like gem2.1.1.gz was left out of the utopic ruby2.1 package.