deb http://apt.llvm.org/focal/ llvm-toolchain-focal-9 main deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-9 main deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main