Fails to build with python 3.8 beta 2 (3.8.0b2)

[gicmo]

Fedora 32 will switch (ChangeProposal to Python 3.8). The latter should be release around 2019-10-21 (3.8 schedule). Currently (1.4) the build fails because the custom swig (swig-modified-6) generates code that uses a deprecated symbol that got removed in 3.8 (_PyObject_GC_UNTRACK). I included a patch in the Fedora rpm to make it compile. It seems that upstream builtin.swg#L120@master also still uses that marco (_PyObject_GC_UNTRACK), so just updating swig will (for now) to solve the issue. Maybe that will change until Python 3.8 is released.

[baldurk]

(Assuming you meant that "updating swig will (for now) not solve the issue"). I'm already pretty committed to maintaining the swig fork indefinitely, so applying that patch should be fine I think. Since this is only in the .swg files it's pretty easy to update, I'll just need to bump the swig fork's version which is a bit tedious.

[gicmo]

@baldurk ah yes, sorry, indeed meant "not solve the issue". This is not super urgent because we have some time until 3.8 is released but I wanted this to be on the radar. Just for the record, the docu for _PyObject_GC_UNTRACK stating "Deprecated since version 3.6: This macro is removed from Python 3.8.". I am a bit puzzled but I don't even see an issue for that on the swig repo.

[gicmo]

I filed a issue swig#1586 and submitted a PR #1587, with a patch that should also be backwards compatible.

[baldurk]

You might be waiting a while, from what I saw before swig isn't a very responsive project. Either way I'll need to manually backport it so I'll take your patch directly whether or not it's merged upstream.

[gicmo]

Upstream took the patch 🎉, since they only support 2.7 and >= 3.2 they even went for the simpler version, which is identical code-wise with the patch I stuck in the RPM. Want me to file a PR against renderdoc's custom swig repo?

[baldurk]

I merged your patch into the branch manually because it can be a bit of a pain to handle the swig fork. I've also updated the tag with that commit above. Thanks for this.