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 was having this error and noticed I had different versions of Ruby installed with HomeBrew, along with many gems that I no longer used. So did a full clean up like this:

$ brew remove --force ruby # remove all versions installed
$ sudo rm -rf /usr/local/lib/ruby # remove all gems and leftover files
$ brew install ruby
$ gem install bundler
$ bundle install

If you don't use a Gemfile, make sure you know which gems to reinstall.