$ git clone -n https://src.fedoraproject.org/rpms/toolbox.git /var/lib/mock/f41-build-side-1-2670873-29066/root/chroot_tmpdir/scmroot/toolbox
Cloning into '/var/lib/mock/f41-build-side-1-2670873-29066/root/chroot_tmpdir/scmroot/toolbox'...
$ git fetch origin bba451ece16ad5c89627e3bf71452e433361fe53:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/toolbox
 * [new ref]         bba451ece16ad5c89627e3bf71452e433361fe53 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bba451e Rebuild against shadow-utils-subid ABI version 5.0.0