Support for the Ruby 2.1 series ended on March 31 2017. See here for details.
Represents an installed gem. This is used for dependency resolution.
Installed sources sort before all other sources
# File rubygems/source/installed.rb, line 13 def <=> other case other when Gem::Source::Lock, Gem::Source::Vendor then -1 when Gem::Source::Installed then 0 when Gem::Source then 1 else nil end end