Updating clang to compile c to wasm

The clang version (7.0.0) that is installed in glitch containers doesn’t support -target wasm32. Is there a way to install/update a newer version (12.0.0) of clang that does support wasm32?

I tried llvm’s automatic installer script bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" but that just failed since it must be run as root