$ git clone -n https://src.fedoraproject.org/rpms/alex.git /var/lib/mock/f41-build-side-1-2645812-27204/root/chroot_tmpdir/scmroot/alex
Cloning into '/var/lib/mock/f41-build-side-1-2645812-27204/root/chroot_tmpdir/scmroot/alex'...
$ git fetch origin 3e500c29420230564bf0b1b6e45aeef9501ba6db:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/alex
 * [new ref]         3e500c29420230564bf0b1b6e45aeef9501ba6db -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3e500c2 https://hackage.haskell.org/package/alex-3.4.0.1/changelog