MarsSeed [1] filed a deletion request for llvm50 [2]: No AUR package needs this abandoned llvm 5.0 from 2018 with misleading name (should have been called llvm5 or llvm-5).
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/llvm50/
