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gtk-doc has been slowly dying for the past few years; with gi-docgen we have a nice successor. This also makes sure the C documentation also uses the GIR file, which in turn means faster build times (since all the C code doesn't have to be parsed and recompiled again), and has a clear dependency graph. See the [gi-docgen tutorial] for more info on how the system works. [gi-docgen tutorial]: https://gnome.pages.gitlab.gnome.org/gi-docgen/tutorial.html