Package: coreutils - Boot arch linux live cd 2022.06. It has coreutils 9.1-1. - mkfs.btrfs /dev/vda - mount /dev/vda /mnt - cp -ax / /mnt cp: cannot create directory '/mnt/': No such file or directory
If relevant: strace says that newfstatat and mkdirat have been given "" as pathname and return ENOENT. Instead, the exact same steps work on arch linux 2022.03, which has coreutils 9.0-2. Note that -x should prevent trying to copy /mnt under itself; on 2022.03, there is a proper error message for cp -a / /mnt without -x.
