$ git clone -n https://src.fedoraproject.org/rpms/btrbk.git /var/lib/mock/f39-build-1530890-36198/root/chroot_tmpdir/scmroot/btrbk
Cloning into '/var/lib/mock/f39-build-1530890-36198/root/chroot_tmpdir/scmroot/btrbk'...
$ git fetch origin 0077a5c5774fe7a7119d3a5772536dffc7323944:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/btrbk
 * [new ref]         0077a5c5774fe7a7119d3a5772536dffc7323944 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0077a5c Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild