$ git clone -n https://src.fedoraproject.org/rpms/gmsh.git /var/lib/mock/f42-build-868657-176222/root/chroot_tmpdir/scmroot/gmsh
Cloning into '/var/lib/mock/f42-build-868657-176222/root/chroot_tmpdir/scmroot/gmsh'...
$ git fetch origin c97049148ef20c09faaf8c651c31f1be187a5c57:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gmsh
 * [new ref]         c97049148ef20c09faaf8c651c31f1be187a5c57 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c970491 Rebuild for tcl/tk