Tried to install a gem on Mountain Lion and make couldn't find gcc-4.2:
kamil$ gem install posix-spawn -v '0.3.6'
Building native extensions. This could take a while...
ERROR: Error installing posix-spawn:
ERROR: Failed to build gem native extension.
/Users/kamil/.rbenv/versions/1.9.3-p0/bin/ruby extconf.rb
creating Makefile
make
compiling posix-spawn.c
make: gcc-4.2: No such file or directory
make: *** [posix-spawn.o] Error 1
If you have Xcode installed, gcc should be available. Check where it is with:
kamil$ which gcc
/usr/bin/gcc
Then make a user-land symbolic link from gcc-4.2 to plain gcc:
kamil$ sudo ln -s ~/bin/gcc /usr/bin/gcc-4.2
(Ensure the user-land bind folder is in your path via export PATH=...:$HOME/bin
in your .bash_profile
or .zshrc
.)
Gem installed fine afterwards.