This only let tarball creation to proceed, whether there is something new needed by autotest needs to be tested by anyone who is in charge.
The new test shows a language nesting regression: With LyX 2.1 it exports fine in all formats, with 2.2 it fails for dvi, pdf2 and pdf3.
Thanks to Kornel we do now have the infrastructure for running dedicated export tests. This is the first one, showing a language nesting bug which is already in 2.1. It is inverted for now, but this will hopefully change soon.