$ git clone -n https://src.fedoraproject.org/rpms/gnome-font-viewer.git /var/lib/mock/f41-build-855166-167072/root/chroot_tmpdir/scmroot/gnome-font-viewer
Cloning into '/var/lib/mock/f41-build-855166-167072/root/chroot_tmpdir/scmroot/gnome-font-viewer'...
$ git fetch origin 2acc12b281ffd45ca2939e07bc049b7e3e800474:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-font-viewer
 * [new ref]         2acc12b281ffd45ca2939e07bc049b7e3e800474 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2acc12b Update to 47.0