$ t
/usr/lib/ruby/2.3.0/rubygems/dependency.rb:319:in `to_specs': Could not find 't' (>= 0) among 19 total gem(s) (Gem::LoadError)
Checked in 'GEM_PATH=/home/dx/.gem/ruby/2.3.0:/usr/lib/ruby/gems/2.3.0', execute `gem env` for more information
        from /usr/lib/ruby/2.3.0/rubygems/dependency.rb:328:in `to_spec'
        from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb:65:in `gem'
        from /usr/bin/t:22:in `<main>'