The current BackLinkFilter only reads page.links(...) (i.e. local wikilinks) and does not read interwiki links such as [[incubator:Wp/sms/...]]. This is why you get BackLinkFilter ready with 0 links.
include_langlinks does not solve this, because it only expands the langlinks() of already-found pages, not the interwiki links of the source page.,
The current BackLinkFilter only reads page.links(...) (i.e. local wikilinks) and does not read interwiki links such as [[incubator:Wp/sms/...]]. This is why you get BackLinkFilter ready with 0 links.
include_langlinks does not solve this, because it only expands the langlinks() of already-found pages, not the interwiki links of the source page.,