+ if [ "$CC" == clang-3.9 ]; then
+ sudo cp .travis-apt-pin.preferences /etc/apt/preferences.d/no-ubuntu-clang;
+ curl -sSL "http://apt.llvm.org/llvm-snapshot.gpg.key" | sudo -E apt-key add -;
+ echo "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.9 main" | sudo tee -a /etc/apt/sources.list > /dev/null;
+ sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test";
+ sudo -E apt-get -yq update;
+ sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install clang-3.9;
+ elif which ccache >/dev/null; then