There's a copypasta error in the sections.txt that breaks the build, fixed by this commit:
While fixing that I also cleaned up some other gtk-doc warnings, in branch smcv/gtk-doc. If you don't want to review the non-essential commits, please leave this bug open and downgrade it to minor.
Your branch all looks good to me.
Thanks. I backported the patches as far as possible before merging: the build failure never affected a release, and the minor issues will be fixed in 0.11.0 and (if released) 0.10.1 and 0.8.2.