ci: install debug interpreter with uv (#5447)

* ci: install debug interpreter with uv

* try use rpath to link to exact interpreter

* don't emit rpath on wasm targets

* fixup clippy

* update now ui-test has landed

* fix clippy

* Update pyo3-build-config/src/lib.rs

Co-authored-by: Thomas Tanon <thomas@pellissier-tanon.fr>

* newsfragment

---------

Co-authored-by: Thomas Tanon <thomas@pellissier-tanon.fr>

Author: davidhewitt

.github/workflows/ci.yml

@@ -597,37 +597,11 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rust-src
-      - name: Install python3 standalone debug build with nox
-        run: |
-          PBS_RELEASE="20241219"
-          PBS_PYTHON_VERSION="3.13.1"
-          PBS_ARCHIVE="cpython-${PBS_PYTHON_VERSION}+${PBS_RELEASE}-x86_64-unknown-linux-gnu-debug-full.tar.zst"
-          wget "https://github.com/indygreg/python-build-standalone/releases/download/${PBS_RELEASE}/${PBS_ARCHIVE}"
-          tar -I zstd -xf "${PBS_ARCHIVE}"
-          ls -l $(pwd)/python/install/bin
-          ls -l $(pwd)/python/install/lib
-          echo PATH=$(pwd)/python/install/bin:$PATH >> $GITHUB_ENV
-          echo LD_LIBRARY_PATH=$(pwd)/python/install/lib:$LD_LIBRARY_PATH >> $GITHUB_ENV
-          echo PYTHONHOME=$(pwd)/python/install >> $GITHUB_ENV
-          echo PYO3_PYTHON=$(pwd)/python/install/bin/python3 >> $GITHUB_ENV
-      - run: python3 -m sysconfig
-      - run: python3 -m pip install --upgrade pip && pip install nox[uv]
-      - run: |
-          PYO3_CONFIG_FILE=$(mktemp)
-          cat > $PYO3_CONFIG_FILE << EOF
-          implementation=CPython
-          version=3.13
-          shared=true
-          abi3=false
-          lib_name=python3.13d
-          lib_dir=${{ github.workspace }}/python/install/lib
-          executable=${{ github.workspace }}/python/install/bin/python3
-          pointer_width=64
-          build_flags=Py_DEBUG,Py_REF_DEBUG
-          suppress_build_script_link_lines=false
-          EOF
-          echo PYO3_CONFIG_FILE=$PYO3_CONFIG_FILE >> $GITHUB_ENV
-      - run: python3 -m nox -s test
+      - uses: astral-sh/setup-uv@v6
+        with:
+          python-version: "3.13+debug"
+      - run: uvx python -m sysconfig
+      - run: uvx nox -s test
 
   test-version-limits:
     needs: [fmt, resolve]

build.rs

@@ -1,9 +1,9 @@
 use std::env;
 
-use pyo3_build_config::pyo3_build_script_impl::{cargo_env_var, errors::Result};
-use pyo3_build_config::{
-    add_python_framework_link_args, bail, print_feature_cfgs, InterpreterConfig,
+use pyo3_build_config::pyo3_build_script_impl::{
+    cargo_env_var, errors::Result, print_feature_cfgs,
 };
+use pyo3_build_config::{add_libpython_rpath_link_args, bail, InterpreterConfig};
 
 fn ensure_auto_initialize_ok(interpreter_config: &InterpreterConfig) -> Result<()> {
     if cargo_env_var("CARGO_FEATURE_AUTO_INITIALIZE").is_some() && !interpreter_config.shared() {
@@ -47,8 +47,8 @@ fn configure_pyo3() -> Result<()> {
     // which allows consumers of `pyo3-build-config` APIs to depend on pyo3 instead of pyo3-ffi.
     interpreter_config.to_cargo_dep_env()?;
 
-    // Make `cargo test` etc work on macOS with Xcode bundled Python
-    add_python_framework_link_args();
+    // Make `cargo test` etc work with non-system Python installations
+    add_libpython_rpath_link_args();
 
     Ok(())
 }

newsfragments/5447.fixed.md

@@ -0,0 +1 @@
+Fix `add_libpython_rpath_link_args` emitting rpath link args on wasm targets which don't support rpath.

pyo3-build-config/src/lib.rs

@@ -18,7 +18,7 @@ pub use impl_::{
     PythonVersion, Triple,
 };
 
-use target_lexicon::OperatingSystem;
+use target_lexicon::{Architecture, OperatingSystem};
 
 /// Adds all the [`#[cfg]` flags](index.html) to the current compilation.
 ///
@@ -95,23 +95,7 @@ fn _add_extension_module_link_args(
 /// for more details.
 pub fn add_libpython_rpath_link_args() {
     let target = impl_::target_triple_from_env();
-    _add_libpython_rpath_link_args(
-        get(),
-        impl_::is_linking_libpython_for_target(&target),
-        std::io::stdout(),
-    )
-}
-
-fn _add_libpython_rpath_link_args(
-    interpreter_config: &InterpreterConfig,
-    is_linking_libpython: bool,
-    mut writer: impl std::io::Write,
-) {
-    if is_linking_libpython {
-        if let Some(lib_dir) = interpreter_config.lib_dir() {
-            writeln!(writer, "cargo:rustc-link-arg=-Wl,-rpath,{lib_dir}").unwrap();
-        }
-    }
+    pyo3_build_script_impl::print_libpython_rpath_link_args(&target, get());
 }
 
 /// Adds linker arguments suitable for linking against the Python framework on macOS.
@@ -162,32 +146,6 @@ fn get_inner() -> InterpreterConfig {
     interpreter_config.expect("failed to parse PyO3 config")
 }
 
-/// Helper to print a feature cfg with a minimum rust version required.
-fn print_feature_cfg(minor_version_required: u32, cfg: &str) {
-    let minor_version = rustc_minor_version().unwrap_or(0);
-
-    if minor_version >= minor_version_required {
-        println!("cargo:rustc-cfg={cfg}");
-    }
-
-    // rustc 1.80.0 stabilized `rustc-check-cfg` feature, don't emit before
-    if minor_version >= 80 {
-        println!("cargo:rustc-check-cfg=cfg({cfg})");
-    }
-}
-
-/// Use certain features if we detect the compiler being used supports them.
-///
-/// Features may be removed or added as MSRV gets bumped or new features become available,
-/// so this function is unstable.
-#[doc(hidden)]
-pub fn print_feature_cfgs() {
-    print_feature_cfg(84, "const_is_null");
-    print_feature_cfg(85, "fn_ptr_eq");
-    print_feature_cfg(86, "from_bytes_with_nul_error");
-    print_feature_cfg(95, "cfg_select");
-}
-
 /// Registers `pyo3`s config names as reachable cfg expressions
 ///
 /// - <https://github.com/rust-lang/cargo/pull/13571>
@@ -328,6 +286,47 @@ pub mod pyo3_build_script_impl {
             self.message
         }
     }
+
+    /// Detects features which `pyo3` and `pyo3-ffi` depend upon internally, and prints the appropriate
+    /// `cargo:rustc-cfg` and `cargo:rustc-check-cfg` directives to enable them.
+    pub fn print_feature_cfgs() {
+        print_feature_cfg(84, "const_is_null");
+        print_feature_cfg(85, "fn_ptr_eq");
+        print_feature_cfg(86, "from_bytes_with_nul_error");
+        print_feature_cfg(95, "cfg_select");
+    }
+
+    /// Helper to print a feature cfg with a minimum rust version required.
+    fn print_feature_cfg(minor_version_required: u32, cfg: &str) {
+        println!("cargo:rustc-check-cfg=cfg({cfg})");
+
+        let minor_version = rustc_minor_version().unwrap_or(0);
+        if minor_version >= minor_version_required {
+            println!("cargo:rustc-cfg={cfg}");
+        }
+    }
+
+    /// Emit libpython rpath link args if appropriate for the target and interpreter config.
+    ///
+    /// This form exists for pyo3-ffi where `get()` cannot be called.
+    pub fn print_libpython_rpath_link_args(
+        target: &Triple,
+        interpreter_config: &InterpreterConfig,
+    ) {
+        let is_linking_libpython = is_linking_libpython_for_target(target);
+        let is_wasm = matches!(
+            target.architecture,
+            Architecture::Wasm32 | Architecture::Wasm64
+        );
+        let is_emscripten = target.operating_system == target_lexicon::OperatingSystem::Emscripten;
+        // webassembly targets generally don't support rpath, emscripten is the only exception currently aware of:
+        // https://github.com/emscripten-core/emscripten/issues/22126
+        if is_linking_libpython && (!is_wasm || is_emscripten) {
+            if let Some(lib_dir) = interpreter_config.lib_dir() {
+                println!("cargo:rustc-link-arg=-Wl,-rpath,{lib_dir}");
+            }
+        }
+    }
 }
 
 fn rustc_minor_version() -> Option<u32> {

pyo3-ffi/build.rs

@@ -1,9 +1,9 @@
 use pyo3_build_config::{
-    bail, ensure, print_feature_cfgs,
+    bail, ensure,
     pyo3_build_script_impl::{
         cargo_env_var, env_var, errors::Result, is_linking_libpython_for_target,
-        resolve_build_config, target_triple_from_env, BuildConfig, BuildConfigSource,
-        MaximumVersionExceeded,
+        print_feature_cfgs, print_libpython_rpath_link_args, resolve_build_config,
+        target_triple_from_env, BuildConfig, BuildConfigSource, MaximumVersionExceeded,
     },
     warn, InterpreterConfig, PythonImplementation, PythonVersion,
 };
@@ -214,12 +214,12 @@ fn emit_link_config(build_config: &BuildConfig) -> Result<()> {
 
 /// Prepares the PyO3 crate for compilation.
 ///
-/// This loads the config from pyo3-build-config and then makes some additional checks to improve UX
-/// for users.
+/// This uses pyo3-build-config implementation to detect the target Python interpreter and validate
+/// it's suitable for building with.
 ///
 /// Emits the cargo configuration based on this config as well as a few checks of the Rust compiler
 /// version to enable features which aren't supported on MSRV.
-fn configure_pyo3() -> Result<()> {
+fn configure_pyo3_ffi() -> Result<()> {
     let target = target_triple_from_env();
     let build_config = resolve_build_config(&target)?;
     let interpreter_config = &build_config.interpreter_config;
@@ -251,6 +251,9 @@ fn configure_pyo3() -> Result<()> {
 
     print_feature_cfgs();
 
+    // Make `cargo test` etc work with non-system Python installations
+    print_libpython_rpath_link_args(&target, interpreter_config);
+
     Ok(())
 }
 
@@ -265,7 +268,7 @@ fn print_config_and_exit(config: &InterpreterConfig) {
 
 fn main() {
     pyo3_build_config::print_expected_cfgs();
-    if let Err(e) = configure_pyo3() {
+    if let Err(e) = configure_pyo3_ffi() {
         eprintln!("error: {}", e.report());
         std::process::exit(1)
     }