Bugs are tracked in LLVM Bugzilla.
Getting started with bug tracking in Launchpad.Ubuntu also tracks bugs for packages derived from this project: clang in Ubuntu, libc++ in Ubuntu, llvm in Ubuntu, llvm-2.7 in Ubuntu, llvm-2.8 in Ubuntu, llvm-2.9 in Ubuntu, llvm-3.0 in Ubuntu, llvm-3.1 in Ubuntu, llvm-3.2 in Ubuntu, llvm-toolchain-14 in Ubuntu, llvm-toolchain-3.2 in Ubuntu, llvm-toolchain-3.3 in Ubuntu, llvm-toolchain-3.4 in Ubuntu, llvm-toolchain-3.5 in Ubuntu, llvm-toolchain-3.6 in Ubuntu, llvm-toolchain-3.7 in Ubuntu, llvm-toolchain-3.8 in Ubuntu, llvm-toolchain-5.0 in Ubuntu.
