$ git clone -n https://src.fedoraproject.org/rpms/gnome-user-docs.git /var/lib/mock/f45-build-11688-434/root/chroot_tmpdir/scmroot/gnome-user-docs
Cloning into '/var/lib/mock/f45-build-11688-434/root/chroot_tmpdir/scmroot/gnome-user-docs'...
$ git fetch origin c3ddd99d73b60098be1c9b305c9dd69100dd7c19:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-user-docs
 * [new ref]         c3ddd99d73b60098be1c9b305c9dd69100dd7c19 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3ddd99 Update to 51.0