Patch embedded install path for Python dylib on macOS during python install (#10629)

## Summary

Fixes #10598 

## Test Plan

Looking for input here @zanieb. How/where would you include tests for
this?
More broadly: do we want a failure to perform the rename to be a hard
error? Or should it start out as a warning?

---------

Co-authored-by: Zanie Blue <contact@zanie.dev>

crates/uv-python/src/installation.rs

@@ -165,6 +165,9 @@ impl PythonInstallation {
         installed.ensure_externally_managed()?;
         installed.ensure_sysconfig_patched()?;
         installed.ensure_canonical_executables()?;
+        if let Err(e) = installed.ensure_dylib_patched() {
+            e.warn_user(&installed);
+        }
 
         Ok(Self {
             source: PythonSource::Managed,

crates/uv-python/src/lib.rs

@@ -30,6 +30,7 @@ mod implementation;
 mod installation;
 mod interpreter;
 mod libc;
+pub mod macos_dylib;
 pub mod managed;
 #[cfg(windows)]
 mod microsoft_store;

crates/uv-python/src/macos_dylib.rs

@@ -0,0 +1,63 @@
+use std::{io::ErrorKind, path::PathBuf};
+
+use uv_fs::Simplified as _;
+use uv_warnings::warn_user;
+
+use crate::managed::ManagedPythonInstallation;
+
+pub fn patch_dylib_install_name(dylib: PathBuf) -> Result<(), Error> {
+    let output = match std::process::Command::new("install_name_tool")
+        .arg("-id")
+        .arg(&dylib)
+        .arg(&dylib)
+        .output()
+    {
+        Ok(output) => output,
+        Err(e) => {
+            let e = if e.kind() == ErrorKind::NotFound {
+                Error::MissingInstallNameTool
+            } else {
+                e.into()
+            };
+            return Err(e);
+        }
+    };
+
+    if !output.status.success() {
+        let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
+        return Err(Error::RenameError { dylib, stderr });
+    }
+
+    Ok(())
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
+    #[error("`install_name_tool` is not available on this system.
+This utility is part of macOS Developer Tools. Please ensure that the Xcode Command Line Tools are installed by running:
+
+    xcode-select --install
+
+For more information, see: https://developer.apple.com/xcode/")]
+    MissingInstallNameTool,
+    #[error("Failed to update the install name of the Python dynamic library located at `{}`", dylib.user_display())]
+    RenameError { dylib: PathBuf, stderr: String },
+}
+
+impl Error {
+    /// Emit a user-friendly warning about the patching failure.
+    pub fn warn_user(&self, installation: &ManagedPythonInstallation) {
+        let error = if tracing::enabled!(tracing::Level::DEBUG) {
+            format!("\nUnderlying error: {self}")
+        } else {
+            String::new()
+        };
+        warn_user!(
+            "Failed to patch the install name of the dynamic library for {}. This may cause issues when building Python native extensions.{}",
+            installation.executable().simplified_display(),
+            error
+        );
+    }
+}

crates/uv-python/src/managed.rs

@@ -25,7 +25,8 @@ use crate::libc::LibcDetectionError;
 use crate::platform::Error as PlatformError;
 use crate::platform::{Arch, Libc, Os};
 use crate::python_version::PythonVersion;
-use crate::{sysconfig, PythonRequest, PythonVariant};
+use crate::{macos_dylib, sysconfig, PythonRequest, PythonVariant};
+
 #[derive(Error, Debug)]
 pub enum Error {
     #[error(transparent)]
@@ -88,6 +89,8 @@ pub enum Error {
     NameParseError(#[from] installation::PythonInstallationKeyError),
     #[error(transparent)]
     LibcDetection(#[from] LibcDetectionError),
+    #[error(transparent)]
+    MacOsDylib(#[from] macos_dylib::Error),
 }
 /// A collection of uv-managed Python installations installed on the current system.
 #[derive(Debug, Clone, Eq, PartialEq)]
@@ -508,6 +511,28 @@ impl ManagedPythonInstallation {
         Ok(())
     }
 
+    /// On macOS, ensure that the `install_name` for the Python dylib is set
+    /// correctly, rather than pointing at `/install/lib/libpython{version}.dylib`.
+    /// This is necessary to ensure that native extensions written in Rust
+    /// link to the correct location for the Python library.
+    ///
+    /// See <https://github.com/astral-sh/uv/issues/10598> for more information.
+    pub fn ensure_dylib_patched(&self) -> Result<(), macos_dylib::Error> {
+        if cfg!(target_os = "macos") {
+            if *self.implementation() == ImplementationName::CPython {
+                let dylib_path = self.python_dir().join("lib").join(format!(
+                    "{}python{}{}{}",
+                    std::env::consts::DLL_PREFIX,
+                    self.key.version().python_version(),
+                    self.key.variant().suffix(),
+                    std::env::consts::DLL_SUFFIX
+                ));
+                macos_dylib::patch_dylib_install_name(dylib_path)?;
+            }
+        }
+        Ok(())
+    }
+
     /// Create a link to the managed Python executable.
     ///
     /// If the file already exists at the target path, an error will be returned.
@@ -603,7 +628,7 @@ impl ManagedPythonInstallation {
 }
 
 /// Generate a platform portion of a key from the environment.
-fn platform_key_from_env() -> Result<String, Error> {
+pub fn platform_key_from_env() -> Result<String, Error> {
     let os = Os::from_env();
     let arch = Arch::from_env();
     let libc = Libc::from_env()?;