$ git clone -n https://src.fedoraproject.org/rpms/nghttp2.git /var/lib/mock/f40-build-2299459-56630/root/chroot_tmpdir/scmroot/nghttp2
Cloning into '/var/lib/mock/f40-build-2299459-56630/root/chroot_tmpdir/scmroot/nghttp2'...
$ git fetch origin 2572b4869bfdf27f076749653e99f5103b73bf6c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nghttp2
 * [new ref]         2572b4869bfdf27f076749653e99f5103b73bf6c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2572b48 update to the latest upstream release (1.59.0)