2nd, submodules do not allow for patching the vendored sources (e.g. we *could* remove the annoying printout at Pa_Initialize() in our vendored copy, but not with 'git submodule').
Actually, you can commit changes to a submodule: https://stackoverflow.com/a/5542964/6063908. However, it's probably cleaner to just make a fork.
what i do care about is that the portaudio backend implementation of Pd remains (API-)compatible with released stable versions of PortAudio (and ideally (API-)compatible with the version of portaudio shipped in major linux distributions, esp. Debian)
Good point! The existing API won't change, but we can't use *new* API functions.
now that it's officially on GitHub?
this i don't really understand. what makes GitHub different from BitBucket, GitLab, SourceForge or git.jackaudio.org with respect to 'git submodule's?
Ah, sorry. What I meant was: "now that PortAudio uses Git (instead of SVN)". However, I just realized that they "already" switched to Git in 2016, before they moved the repo to GitHub.