Must provide PYO3_CROSS_LIB_DIR environment variable

[jdaruja]

🐛 Bug Reports

When reporting a bug, please provide the following information. If this is not a bug report you can just discard this template.

🌍 Environment

• Your operating system and version: Unbuntu 20.4
• Your python version: 3.8
• How did you install python (e.g. apt or pyenv)? Did you use a virtualenv?: apt / virtualenv- yes
• Your Rust version (rustc --version):1.51.0
• Your PyO3 version: 0.13.2
• Have you tried using latest PyO3 main (replace version = "0.x.y" with git = "https://github.com/PyO3/pyo3")?: yes

💥 Reproducing

lib.rs

use pyo3::prelude::;
use pyo3::wrap_pyfunction;
use std::fs::File;
use std::io::prelude::;
use std::path::Path;

#[allow(unused_parens)]
#[pyfunction]
/// Returns the file
fn return_file(a: String) -> PyResult {
let mut f = File::open(a)?;
let mut contents = String::new();
f.read_to_string(&mut contents)?;
Ok((contents))
}

/// This module is a python module implemented in Rust.
///
#[pymodule]
fn cross_compile(py: Python, m: &PyModule) -> PyResult<()> {
m.add_wrapped(wrap_pyfunction!(return_file))?;
Ok(())
}

---

When I cross build using - cross-rs/cross#556 instructions (Embedded/Rust)
after setting environment variable "PYO3_CROSS_LIB_DIR" using export PYO3_CROSS_LIB_DIR = "/usr/lib".
using command

$ cross build --target aarch64-unknown-linux-gnu

I am getting below error -

Error: "Must provide PYO3_CROSS_LIB_DIR environment variable when cross-compiling"

When I run $ echo $PYO3_CROSS_LIB_DIR, it shows /usr/lib.

Please help

[davidhewitt]

Thanks for the question @jdaruja .

cross runs compilation inside a Docker container. To pass environment variables to the compilation you must follow the instructions at https://github.com/rust-embedded/cross#passing-environment-variables-into-the-build-environment

e.g. add this to your Cross.toml:

[build.env]
passthrough = [
    "PYO3_CROSS_LIB_DIR",
]