I\'ve installed gcc-4.6 using the homebrew-alternatives gcc formula, but I can\'t seem to get it to use that GCC to install other formulas. Specifi
Homebrew can't adapt to other versions of gcc using command line options. You can easily override the older compiler, though, if you edit the open-mpi and boost formula. For example, you can add a few commands after the "def install" in open-mpi.rb:
def install
# Force compilation with gcc-4.6
ENV['CC'] = '/usr/local/bin/gcc-4.6'
ENV['LD'] = '/usr/local/bin/gcc-4.6'
ENV['CXX'] = '/usr/local/bin/g++-4.6'
# Compiler complains about link compatibility with FORTRAN otherwise
ENV.delete('CFLAGS')
ENV.delete('CXXFLAGS')
That worked for me on Lion. Good luck.