$ git clone -n https://src.fedoraproject.org/rpms/kde-gtk-config.git /var/lib/mock/f42-build-side-114485-60910440-6585495/root/chroot_tmpdir/scmroot/kde-gtk-config
Cloning into '/var/lib/mock/f42-build-side-114485-60910440-6585495/root/chroot_tmpdir/scmroot/kde-gtk-config'...
$ git fetch origin 859d52f605de6b6afb6eacc92def354332122d99:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kde-gtk-config
 * [new ref]         859d52f605de6b6afb6eacc92def354332122d99 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 859d52f 6.4.2