I tried to install a gem by using gem-install command in pry, but it failed.
% pry
pry(main) > gem-install pry-doc
NoMethodError: undefined method `split' for nil:NilClass
from /Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/pry-0.10.1/lib/pry/rubygem.rb:60:in `install'
I could install the gem by using gem command from bash.
Is there something I must configure to use gem-install command in pry?