$ git clone -n https://src.fedoraproject.org/rpms/pygobject3.git /var/lib/mock/f40-build-2633086-65919/root/chroot_tmpdir/scmroot/pygobject3
Cloning into '/var/lib/mock/f40-build-2633086-65919/root/chroot_tmpdir/scmroot/pygobject3'...
$ git fetch origin 25e548ffc8a249db2f6466ab40989372db2476f9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pygobject3
 * [new ref]         25e548ffc8a249db2f6466ab40989372db2476f9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 25e548f Update sources