Bug report

On Windows, with Python 3.11, an embedded Python interpreter prints a new warning at startup Could not find platform dependent libraries <exec_prefix>.

3.10 and older versions do not exhibit this.

Sample program (I'm using Rust / PyO3 because it's what I know, however I'm fairly sure that it's not relevant to the repro. If you've got a recommended way to configure a windows C toolchain for building an embedded Python I'd be happy to demonstrate the same issue in C):

fn main() {
    unsafe { 
        pyo3::ffi::Py_Initialize();
        dbg!(pyo3::ffi::Py_IsInitialized());
    }
}

Running outputs:

Could not find platform dependent libraries <exec_prefix>
[src\main.rs:4] pyo3::ffi::Py_IsInitialized() = 1

Execution then proceeds without issue. (We observe this in PyO3's test suite, which passes all 3.11 tests despite emitting this warning.)

I have a couple of thoughts:

• Documentation for exec_prefix suggests it is irrelevant on Windows. So is this warning actually useful?
• I suspect this is because of the reimplementation of getpath into Python? (Rewrite getpath.c in Python #89745)

Your environment

• CPython versions tested on: 3.11.0
• Operating system and architecture: Windows x64

• PR: gh-98790: Disable pathconfig warnings except when verbose mode is enabled #98933

• PR: gh-98790: When DLLs directory is missing on Windows, assume executable_dir contains PYD files instead #98936

• PR: [3.11] gh-98790: When DLLs directory is missing on Windows, assume executable_dir contains PYD files instead (GH-98936) #99019