I don\'t manage to install therubyracer gem on Yosemite 10.10.
Here is the log:
11:53 $ gem install libv8 -v \'3.16.14.3\' -- --with-system-v8
Building
Maybe it will be useful for someone but I had problems installing therubyracer (because of the problems with libv8) the solution was to uninstall all the libv8 that I had installed. Install therubyracer
$ gem uninstall libv8
$ gem install therubyracer -v '0.12.0'
Fetching: libv8-3.16.14.7-x86_64-darwin-14.gem ( 57%)
Fetching: libv8-3.16.14.7-x86_64-darwin-14.gem (100%)
Successfully installed libv8-3.16.14.7-x86_64-darwin-14
Building native extensions. This could take a while...
Successfully installed therubyracer-0.12.0
2 gems installed
I hope this helps someone.