Hello, I'm the maintainer of mongodb in MacPorts, trying to update our port from 3.0.8 to 3.2.3.

Running scons with --variables-files=etc/scons/compilers_from_env.vars works, to the extent that the CC and CXX environment variables are imported into scons, but the build fails later because it can't find OpenSSL, because it doesn't know to look for it in our custom prefix.

Additionally setting CPPPATH and LIBPATH in the environment and running scons with --variables-files=etc/scons/propagate_shell_environment.vars does not work; nothing is imported from the environment, not even CC nor CXX.

Specifying the path to a custom vars file containing

import os

CC=os.environ['CC']
CPPPATH=os.environ['CPPPATH']
CXX=os.environ['CXX']
LIBPATH=os.environ['LIBPATH']

works but I shouldn't have to do that.