试图在 Mountain Lion 上安装 gem 并且找不到 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