It was failing to generate doc with recent version of gtk-doc
[kmod]$ ./bootstrap
libkmod/docs/gtk-doc.make:33: error: EXTRA_DIST must be set with '=' before using '+='
libkmod/docs/Makefile.am:29: 'libkmod/docs/gtk-doc.make' included from here
autoreconf: automake failed with exit status: 1
Just add an empty EXTRA_DIST so it works.
Current limitation is horrible no support to sections: we have to to
have separate header files or to maintain the libkmod-sections.txt file.
We are doing the latter.