y u no work!!
SetUnitLineage must be removed, it is used in several places and ie after the commander can not move anymore after upgrading due to lua errors

viewtopic.php?f=14&t=26358&p=493353 etc

Why was setunitlineage removed? How do we now set the lineage to a morphed commander then?

Anyway it's not like lineage matters since game end condition is removed too....

Ok, that's a good explanation.

Do we need to make all widgets backwards compatible? I believe 0.83 has a new function that is called "Spring.PlaySoundStream()", which I believe isn't supported in previous versions. How do I check for a spring version, is there a function such as "Spring.getVersion()" ?

yes there is. there are at least two even, and they are documented on the wiki.

Okay, but it turned out the PlaySoundStream works already, it's just that it doesn't work with a mono vorbis file (needs stereo), whereas PlaySoundFile does work with that.

That's not documented in the wiki and took me some time to sort out