$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-vaapi.git /var/lib/mock/f40-build-795545-140206/root/chroot_tmpdir/scmroot/gstreamer1-vaapi
Cloning into '/var/lib/mock/f40-build-795545-140206/root/chroot_tmpdir/scmroot/gstreamer1-vaapi'...
$ git fetch origin 33c39d41e06f0d59c43f2e5641721faecc4fd29a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-vaapi
 * [new ref]         33c39d41e06f0d59c43f2e5641721faecc4fd29a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 33c39d4 1.22.9