$ git clone -n https://src.fedoraproject.org/rpms/build2.git /var/lib/mock/f41-build-854363-166847/root/chroot_tmpdir/scmroot/build2
Cloning into '/var/lib/mock/f41-build-854363-166847/root/chroot_tmpdir/scmroot/build2'...
$ git fetch origin 48ac26f7fb53394eb6082e823cd5ecf81a872aa5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/build2
 * [new ref]         48ac26f7fb53394eb6082e823cd5ecf81a872aa5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 48ac26f Disable bootstrap and bump release