Hi, At Mapbox we have been using the llvm-toolchain-precise-3.5 package source to install clang-3.5 on Travis CI VMs for testing purposes (Travis VM images are Ubuntu 12.04). This has worked fairly well for us; thanks for providing it. However, the 3.5 source seems to have recently disappeared, breaking our builds. No problem, we thought, we'll update to 3.6. However, this doesn't seem to work either. When using either the llvm-toolchain-precise or llvm-toolchain-precise-3.6 sources, no clang-3.6 package can be found: $ sudo -E apt-add-repository -y "deb http://llvm.org/apt/precise/ llvm-toolchain-precise main" Installing APT Packages (BETA) $ export DEBIAN_FRONTEND=noninteractive $ sudo -E apt-get -yq update &>> ~/apt-get-update.log $ sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install gdb clang-3.6 libstdc++-4.9-dev libstdc++6 libllvm3.4 xutils-dev libxxf86vm-dev x11proto-xf86vidmode-dev mesa-utils Reading package lists... Building dependency tree... Reading state information... E: Unable to locate package clang-3.6 Full output here: https://travis-ci.org/mapbox/mapbox-gl-native/jobs/81888110 Similar output when using the llvm-toolchain-precise-3.6 source here: https://travis-ci.org/mapbox/mapbox-gl-native/jobs/81865117 Are there packages missing from these sources? What version is the unsuffixed llvm-toolchain-precise source expected to contain? And for the future avoidance of unexpected build breakage, is there a setup we can use where packages won't disappear from underneath us? Thanks! John