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=...:$HOME/bin in your .bash_profile or .zshrc.)
Gem installed fine afterwards.
Install simply apple-gcc42 with brew. It generate gcc-4.2 .
brew install apple-gcc42 So we do not need symlinks, which apple update may remove.
As @Artur Bodera mentioned modern OSX will refuse to let you create the symlink in the systems /bin folder.
To avoid this simply create the symlink to your users bin folder
ln -s ~/bin/gcc /usr/bin/gcc-4.2 Don't forget to add the bin folder to your .zshrc or .bash_profile - e.g.
export PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:$HOME/bin