Docs fail to build with gtk-doc 1.30
I presume this was triggered by an upgrade of gtk-doc from 1.29 to 1.30, since librsvg 2.44.13 built fine before.
make[2]: Entering directory '/build/librsvg/src/librsvg/doc'
DOC Preparing build
DOC Building XML
DOC Scanning header files
DOC Introspecting gobjects
DOC Building XML
./rsvg-sections.txt:39: warning: No declaration found for RsvgSizeFunc.
./rsvg-sections.txt:96: warning: No declaration found for librsvg_version.
See rsvg-undeclared.txt for the list of undeclared symbols.
./rsvg-unused.txt:1: warning: 17 unused declarations. They should be added to rsvg-sections.txt in the appropriate place.
DOC Building HTML
../xml/rsvg-handle.xml:107: namespace error : Namespace prefix xlink for href on link is not defined
xlink:href="https://www.w3.org/TR/SVG/">SVG 1.1</link> data. It also
^
warning: failed to load external entity "../xml/tree_index.sgml"
../rsvg-docs.xml:133: element include: XInclude error : could not load ../xml/tree_index.sgml, and no fallback was found
make[2]: *** [Makefile:827: html-build.stamp] Error 6
make[2]: Leaving directory '/build/librsvg/src/librsvg/doc'librsvg 2.44.13 and 2.44.14.