I'm not sure if this is a packaging problem or an upstreams problem, but at least in phase2v12 /usr/share/doc/xlibs-dev contains a large number of symbolic links to files that don't exist. For instance XwcTextPropertyToTextList.3x.html is a link to XmbTextListToTextProperty.3x.html (rather than to the existing XmbTextListToTextProperty.3.html).
Or did I miss something obvious (again)? That wouldn't be the first time... Torbjörn Andersson