Slew of deprecation warnings for protobuf descriptors

[Terrance]

When using protobuf==3.13.0 on Python 3.9:

hangups/hangouts_pb2.py:19: DeprecationWarning: Call to deprecated create function FileDescriptor(). Note: Create unlinked descriptors is going to go away. Please use get/find descriptors from generated code or query the descriptor_pool.
hangups/hangouts_pb2.py:33: DeprecationWarning: Call to deprecated create function EnumValueDescriptor(). Note: Create unlinked descriptors is going to go away. Please use get/find descriptors from generated code or query the descriptor_pool.
(one for each declaration)

[tdryer]

I can't reproduce those warnings.

Are they triggered when you run this command?

python -W default -c "import hangups"

[tdryer]

The warnings are only showing up with Python 3.9 because there's no protobuf wheel for Python 3.9 yet, so it defaults to the Python implementation instead of the C++ implementation. Only the Python implementation raises DeprecationWarning.

We can eliminate the warnings by recompiling the proto files using a newer version of protoc (at least 3.12), but this will also require increasing the minimum protobuf package version.

[Terrance]

Yes, I'm using -X dev, which implies -W default. Looks like the unlinked descriptors were deprecated back in April, but there's no obvious timescale for their removal (e.g. they're still there in the 4.0 RC).

Looks like we can put up with the warnings for now, and we're waiting on protocolbuffers/protobuf#7978 for a supported C++ build.

[steveoh]

with pytest i can ignore these in my setup.cfg with

filterwarnings =
    ignore:Call to deprecated create function FieldDescriptor
    ignore:Call to deprecated create function Descriptor
    ignore:Call to deprecated create function EnumDescriptor
    ignore:Call to deprecated create function EnumValueDescriptor
    ignore:Call to deprecated create function FileDescriptor
    ignore:Call to deprecated create function OneofDescriptor

[Terrance]

protobuf v3.15 has been released with py39 wheels -- can we get a requirements bump to <3.16?

[Terrance]

We've got v0.4.13 with the requirements bump now, so I think we're good to close this. 👍