You seem to have forgotten to enable the reference entity in book.xml
(&reference.gearman.reference;).
The functions seem to have a bunch of autogenerated text which should
be removed.
Actually, I left out that one on purpose. The focus at the Gearman site is
on the OO interface, so I decided in the initial documentation I'd also
focus on the OO stuff as well and omit the functions. In this case, should I
remove the function XML files? (I'm guessing yes :))
Ideally at least the skeletons (minus the autogenerated text) would be added, but beginning with (and focusing on) one part (like OOP) is perfectly fine too.
And I'll add a "Don't insert autogenerated text" option to docgen, for those of us in the know.
Regards,
Philip