mypy fails to identify stubs when defined in custom requirements file

[Adityav2410]

I have a separete resolve for mypy and its equivalent mypy-requiremnts.txt. originally saw this problem when running with protobufs. So my code uses a number of third party libraries, redis, requests and protobuf. I see 2 issues as described below:

1. If my stubs types-requests, types-redis are defined in python-default resolved (requirements.txt), everything passes when i run pants check ::, but when i move these requiements from default requirements.txt to mypy-requirements.txt (and regenerate lockfiles), mypy fails complaining that it cannot find stubs for these libraries.
2. Error with types-protobuf. So my code also uses protobuf and i am using mypy_plugin=true in pants.toml. If i put types-protobuf as dependency in any requirements file(default requirements.txt or mypy-requirements.txt), mypy fails to detect stubs, complaining Library stubs not installed for "google.protobuf.message". But if i add this extra stub in mypy section of pants.toml like extra_type_stubs = ["types-protobuf"], my pants check :: passes.

So overall it seems like, mypy doesn't evaluate the dependencies defined in mypy-requirements.txt when using an explicit resolve for mypy. Also in particular for protobuf, it fails to detect types-protobuf unless i pass it explicitly in [mypy] section of pants.toml.

Can someone help me identify what i could be doing wrong? I am on mac m1.