GI-DocGen is a document generator for GObject-based libraries. GObject
 is the base type system of the GNOME project. GI-Docgen reuses the
 introspection data generated by GObject-based libraries to generate
 the API reference of these libraries, as well as other ancillary
 documentation.
 .
 GI-DocGen is not a general purpose documentation tool for C libraries:
 while GI-DocGen can be used to generate API references for most GObject/C
 libraries that expose introspection data, its main goal is to generate
 the reference for GTK and its immediate dependencies.
 .
 GI-DocGen is still in development. The upstream-recommended use of
 GI-DocGen is to add it as a sub-project to a Meson build system, and
 vendor it when releasing dist archives. Until GI-DocGen becomes stable,
 Debian packages that use it for their documentation should use a vendored
 copy (as allowed by Policy §4.13), and should not have a Build-Depends
 on gi-docgen unless no vendored copy is present in upstream releases.