$ git clone -n https://src.fedoraproject.org/rpms/rust-arbitrary.git /var/lib/mock/f39-build-1444670-32628/root/chroot_tmpdir/scmroot/rust-arbitrary
Cloning into '/var/lib/mock/f39-build-1444670-32628/root/chroot_tmpdir/scmroot/rust-arbitrary'...
$ git fetch origin 6c15b47db6d436ac72f15aa6a5ab37e260090aa7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-arbitrary
 * [new ref]         6c15b47db6d436ac72f15aa6a5ab37e260090aa7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6c15b47 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild