page.rdf.covered is false for covered resources

[white-gecko]

graph:

<http://example.org/nocovered#a> a <http://example.org/anchor> .
<http://example.org/super> a <http://example.org/res> .
<http://example.org/super#anchor> a <http://example.org/anchor> .

template:

{{ page.rdf.covered }}

config: graph and template as default_template

actual: super.html: false nocovered.html: false

expected: super.html: true nocovered.html: false