I got it. libsndfile is actually quite common and can be installed very easily on any linux distro from the official repository, no need to build it. That's all you need to build the library and the two programs AAFInfo and AAFExtract.
However, since the only way of creating an Ardour session relies on Ardour itself, the program AAF2Ardour ardour_aafimport needs Ardour6 libraries and headers. So there might be a need to build Ardour6, but AAF2Ardour ardour_aafimport was only a proof of concept, nothing very serious.
A developer who understands Ardour / Mixbus architectures could write a new program that "simply" creates a new empty session and import AAF data into it. I just committed a very basic example source file to show library usage : github.com/agfline/LibAAF/blob/master/example/global_aaf_parsing.c
However, since the only way of creating an Ardour session relies on Ardour itself, the program AAF2Ardour ardour_aafimport needs Ardour6 libraries and headers. So there might be a need to build Ardour6, but AAF2Ardour ardour_aafimport was only a proof of concept, nothing very serious.
A developer who understands Ardour / Mixbus architectures could write a new program that "simply" creates a new empty session and import AAF data into it. I just committed a very basic example source file to show library usage : github.com/agfline/LibAAF/blob/master/example/global_aaf_parsing.c