$ git clone -n https://src.fedoraproject.org/rpms/btrfs-assistant.git /var/lib/mock/f39-build-1517837-35776/root/chroot_tmpdir/scmroot/btrfs-assistant
Cloning into '/var/lib/mock/f39-build-1517837-35776/root/chroot_tmpdir/scmroot/btrfs-assistant'...
$ git fetch origin 28d9a115802a60b7ade08f826d66ecc21d839ba3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/btrfs-assistant
 * [new ref]         28d9a115802a60b7ade08f826d66ecc21d839ba3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 28d9a11 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild