rust-lang/rust — pull request #18194 by jmesmon (2014-10-20 20:26:20+00:00)
Title: mk/rt: "export CC" does not seem to work (gcc observed), use explicit shell variables instead

This was run into while attempting to integrate rust with bitbake's build system. I expect it's caused by some other environment variables being set to gcc but didn't track down the exact cause myself.