The Asuna branch passed.
PS: OK, adding a few parameters of the modification may break the attempt, e.g. L-SMASH headers need to be found if I want to enable MP4 output...
Seems I could create a build with AVS and VPY input and MKV output, yet without LAVF input and without MP4 output. And with unknown version. To be tested...
Works with AviSynth input and MKV output.