I have recently reinstalled ruby 2.1.2 like so since I wanted to install a gem (ruby-debug-ide)
ruby-debug-ide
sudo rvm reinstall 2.1.2 --disable-binary --with
My ENV: Ruby: 2.2.1, Rails: 4.2.1, macOS Sierra 10.12.4;
The below command works for me and my colleague:
ln -s /usr/local/opt/readline/lib/libreadline.7.0.dylib /usr/local/opt/readline/lib/libreadline.6.dylib