Meanwhile, I knew that we had to update all our Github actions soonish due to the deprecation of the old nodejs versions used by them, and I was working towards that, but was hoping to have slightly more time.
Seems some actions have updated the nodejs version on their own, and unfortunately its incompatible with the Ubuntu version used by the Linux dockerfile, so the build is failing there now.
I'll look into updating it to 20.04, just need to figure out how to handle a package that's presenting a choice at install time.