inhzus [1] filed an orphan request for cppcoro-git [2]:

The package script is still under clang 8, so that users with clang 11 (which is installed by default) could not install it correctly. And The maintainer has not resolved the issue mentioned in the comment last June.

[1] https://aur.archlinux.org/account/inhzus/ [2] https://aur.archlinux.org/pkgbase/cppcoro-git/