$ git clone -n https://src.fedoraproject.org/rpms/samba.git /var/lib/mock/f42-build-3350042-45010/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/f42-build-3350042-45010/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin 0cb9860a40530163c1f6893ed04e7e4d59d5757a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/samba
 * [new ref]         0cb9860a40530163c1f6893ed04e7e4d59d5757a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0cb9860 Turn on SMB 3.1.1 Unix Extensions in default smb.conf