MR: https://gitlab.archlinux.org/archlinux/packaging/packages/pacman/-/merge_requests/1

An issue: https://gitlab.archlinux.org/pacman/pacman/-/issues/91

To find your already installed debug packages:

pacman -Q | grep -e '-debug '

This debug packages usually huge, I noticed this accidentally, and I haven’t found a news about this on archlinux.org

To solve this add a ! before debug on line 97 in /etc/makepkg.conf