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

I also struggled with the same failures with rvm install ruby-2.0.0 for many, MANY hours. I had tried all the different methods to install libyaml; wget source, yum and rvm. I also tried all of the different approaches listed in similar threads. Because I tried all the different methods, I had multiple installations and locations of libyaml.

RVM is perfectly capable of installing the necessary dependencies in ~/.rvm. Simply removing the libyaml files from non-RVM install fixed this issue for me:

sudo rm /usr/local/lib/libyaml*.*

rvm reinstall ruby-2.0.0-p0

Works!