language: rust
matrix:
    include:
        - env: CC_X=gcc-4.6 CXX_X=g++-4.6
    allow_failures:
        - rust: nightly

language: rust
matrix:
    include:
        - env: CC_X=gcc-4.8 CXX_X=g++-4.8
          addons:
              apt:
                  packages:
                    - gcc-4.8
    allow_failures:
        - rust: nightly

Install gcc 4.8 via `apt`
Install gcc 4.8 via `apt`
