Should this be marked @type_check_only? There seems to be some precedence for using it on some similar typeddicts, e.g.

Also, to bikeshed the name, I see setuptools internally calls this structure a build_info in a few places, so maybe _BuildInfo would be a good fit?

Interesting, I wasn't aware of it, but likely what we want here. Thanks for the callout. Agree that's a better name here.

f0d929f

Normally I'd prefer defining such types close to where their implementation stands (so with the appropriate Command or Distribution) but in this case it'd end up in distutils and/or setuptools/_distutils so I guess in setuptools.__init__.py is fine.

I do have a concern using a type-only TypedDict with required members as a parameter: It makes it annoying to use a non-literal dict. Maybe that's ok in setuptools due to the nature of it looking like a config file, it shouldn't be much more complex than my example below?

It's possible, but requires a private type-only import, which isn't great:

from typing import cast, TYPE_CHECKING
if TYPE_CHECKING:
    from setuptools import _BuildInfo

libs = [
    ("lib1", {"sources": []}),
    ("lib2", {"sources": []}),
]
setup(libraries=libs)  # Type error in both mypy and pyright due to missing "sources"
# Ok, but must quote type to avoid runtime error
setup(libraries=cast(list[tuple[str, "_BuildInfo"]], libs))
# Ok
setup(libraries=[("literal", {"sources": []})])
# Ok
libs_annotated: list[tuple[str, "_BuildInfo"]] = [ # Must quote type or use from __future__ import annotations
    ("lib1", {"sources": []}),
    ("lib2", {"sources": []}),
]
setup(libraries=libs_annotated)

Yeah, perhaps it's not ideal but I'm not seeing a great alternative, obviously passing things in-line solves this problem, or just:

libs: "list[tuple[str, _BuildInfo]]" = [
    ("lib1", {"sources": []}),
    ("lib2", {"sources": []}),
]
setup(libraries=libs)

Which would work without quotes given deferred annotations.

At the same time, the kind of people to type-check their setup.py are probably the same going all out on typing (looking at myself here ^^)

Are you sure this isn't tuple[str, ...]? In other words, is this really always a one-tuple? (A few more times below.)

You're right, I also glanced over that...
(same for all definitions below)

The one tuple for macros is correct, but the others were a mistake: 2bb4ed4