$ git clone -n https://src.fedoraproject.org/rpms/picard.git /var/lib/mock/f39-build-1459098-33105/root/chroot_tmpdir/scmroot/picard
Cloning into '/var/lib/mock/f39-build-1459098-33105/root/chroot_tmpdir/scmroot/picard'...
$ git fetch origin f46376fceb3b849e01e04709cd11d0626e34dc07:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/picard
 * [new ref]         f46376fceb3b849e01e04709cd11d0626e34dc07 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f46376f rhbz#2240744