how to solve “ruby installation is missing psych” error?

Question

I used rvm to install ruby 1.9.3. even though it was successfully installed, it complained about libyaml. and now every time i wanna install a gem (say rails) this warning s

Answer 1

This is what worked for me on Ubuntu:
- installing libyaml-dev (sudo apt-get install libyaml-dev)
- installing rvm + ruby 1.9.3