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
I built the libyaml files separately from source and installed them in /usr/local/lib. The ruby that RVM created still did not see them, and rather than muck with the makefile or the system LD_LIBRARY_PATH I just copied /usr/local/lib/libyaml* to ~/.rvm/rubies/ruby-1.9.3-p327/lib/
That quieted the warning.