$ git clone -n https://src.fedoraproject.org/rpms/git.git /var/lib/mock/f42-build-side-1-3499983-45966/root/chroot_tmpdir/scmroot/git
Cloning into '/var/lib/mock/f42-build-side-1-3499983-45966/root/chroot_tmpdir/scmroot/git'...
$ git fetch origin 98e46f1051db75a45cba51f587d38f62d08e3de0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/git
 * [new ref]         98e46f1051db75a45cba51f587d38f62d08e3de0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 98e46f1 update to 2.49.0