how do I point build-system.requires package to parent directory.

[Vizonex]

I ran into a pretty nasty problem when writing a new test package for giving the library propcache brand new cython support and a second library multidict which needs the same treatement in order to compile testcapi from a workflow.

The first one which is the one I am going to talk about fixing which should remedy the second one involves pointing to the parent directory where another pyproject.toml file should be located.

mypath -> v
       pyproject.toml (
       This is the one I want to compile without @ git+... and instead point to the parent directory so that propcache compiles)
|
 pyproject.toml (this is the file we want to reach)

The repo is https://github.com/Vizonex/propcache/tree/cython-support with the problem. that I would like fixed so that all workflows or branches can be supported. without it Cython can't compile with propcache correctly.

For those who are too lazy to dig it out I'll show it's current toml file for testcythonapi/pyproject.toml

[project]
name = "testcythonapi"
version = "0.1.0"
description = "Test Module for testing propcache cython api DO NOT UPLOAD TO PYPI!!!"
requires-python = ">=3.9"
classifiers = [
    "Private :: Do Not Upload"
]

[build-system]
# TODO: We need to find a better way to hack in propcache
# get it to compile using the relative path aka parent directory.
# The only problem now is hacking it in to prove it compiles
requires = ["setuptools", "cython", "propcache @ git+https://github.com/Vizonex/propcache@cython-support"] # I would like to transform this url to point to whatever parent directory is used on any github branch.
build-backend = "setuptools.build_meta"

[tool.setuptools]
ext-modules = [
    {name = "testcythonapi.api", sources = ["testcythonapi/api.pyx"]}
]

[webknjaz]

Looks like you're confusing runtime and build deps. build-system is for PEP 517 interactions. You shouldn't need arbitrary deps in that env even if you figure out how. Build backends (like setuptools) don't do anything with that part of pyproject.toml. It's the build frontends (like pypa/build or pip) that use it to populate throwaway tmp envs.

[Vizonex]

Alright sounds good I'll take this as the answer then.