Add test for rust stat64 abi mismatch

This tests the fix for rust-lang/rust#131467 in pyodide/pyodide-build#40.
The problem is that rust cannot correctly read file metadata because the ABI of
fstat64 changed between the version of emscripten that the rust compiler built
the standard library against and our version of the rust compiler.

By passing `-Zbuild-std` we rebuild the rust standard library with the correct
abi. I also added a test that works only if we pass `-Zbuild-std`.

Makefile.envs

@@ -11,8 +11,8 @@ export PYTHON_ARCHIVE_SHA256=d01ec6a33bc10009b09c17da95cc2759af5a580a7316b3a446e
 # to your fork to test the changes are working as expected.
 
 # v0.27.3
-export PYODIDE_BUILD_COMMIT=fac0109aa2acf14469320b049d710dd42639bf94
-export PYODIDE_BUILD_REPO=https://github.com/pyodide/pyodide-build
+export PYODIDE_BUILD_COMMIT=e6928ea61533989063f4ca97138a5dc684144b3d
+export PYODIDE_BUILD_REPO=https://github.com/hoodmane/pyodide-build
 
 ifdef CPYTHON_DEBUG
 	export CPYTHON_ABI_FLAGS=d

packages/rust-abi-test/meta.yaml

@@ -0,0 +1,10 @@
+package:
+  name: rust-abi-test
+  version: "1.0"
+source:
+  path: src
+requirements:
+  executable:
+    - rustup
+about:
+  license: MPL-2.0

packages/rust-abi-test/src/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "rust-abi-test"
+version = "0.1.0"
+edition = "2018"
+publish = false
+
+[dependencies]
+pyo3 = { version = "0.22.3" }
+
+[features]
+extension-module = ["pyo3/extension-module"]
+default = ["extension-module"]
+
+[lib]
+crate-type = ["cdylib"]
+
+[profile.release]
+lto = "thin"
+overflow-checks = true

packages/rust-abi-test/src/pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools", "wheel", "setuptools-rust"]
+build-backend = "setuptools.build_meta"

packages/rust-abi-test/src/setup.py

@@ -0,0 +1,12 @@
+from setuptools import setup
+from setuptools_rust import Binding, RustExtension
+
+setup(
+    name="rust_abi_test",
+    version="1.0",
+    rust_extensions=[
+        RustExtension("rust_abi_test", "Cargo.toml", binding=Binding.PyO3)
+    ],
+    # rust extensions are not zip safe, just like C-extensions.
+    zip_safe=False,
+)

packages/rust-abi-test/src/src/lib.rs

@@ -0,0 +1,17 @@
+use std::fs;
+use pyo3::prelude::*;
+
+
+#[pyfunction]
+fn get_file_length(data: &str) ->  PyResult<u64> {
+    let metadata = fs::metadata(data)?;
+    Ok(metadata.len())
+}
+
+
+
+#[pymodule]
+fn rust_abi_test(m: &Bound<'_, PyModule>) -> pyo3::PyResult<()> {
+    m.add_function(wrap_pyfunction!(get_file_length, m)?)?;
+    Ok(())
+}

packages/rust-abi-test/test_rust_abi.py

@@ -0,0 +1,11 @@
+from pytest_pyodide import run_in_pyodide
+
+@run_in_pyodide(packages=["rust-abi-test"])
+def test_rust_abi(selenium):
+    from pathlib import Path
+    from rust_abi_test import get_file_length
+
+    contents = "this is the contents of the file\n" * 4
+    Path("/test.txt").write_text(contents)
+    assert get_file_length("/test.txt") == len(contents)
+