Use PYO3_CROSS_LIB_DIR as libs dir for #375

Readme.md

@@ -28,7 +28,7 @@ There are three main commands:
 
 `pyo3` and `rust-cpython` bindings are automatically detected, for cffi or binaries you need to pass `-b cffi` or `-b bin`. maturin doesn't need extra configuration files and doesn't clash with an existing setuptools-rust or milksnake configuration. You can even integrate it with testing tools such as [tox](https://tox.readthedocs.io/en/latest/). There are examples for the different bindings in the `test-crates` folder.
 
-The name of the package will be the name of the cargo project, i.e. the name field in the `[package]` section of Cargo.toml. The name of the module, which you are using when importing, will be the `name` value in the `[lib]` section (which defaults to the name of the package). For binaries it's simply the name of the binary generated by cargo.
+The name of the package will be the name of the cargo project, i.e. the name field in the `[package]` section of Cargo.toml. The name of the module, which you are using when importing, will be the `name` value in the `[lib]` section (which defaults to the name of the package). For binaries, it's simply the name of the binary generated by cargo.
 
 ## Python packaging basics
 

src/build_options.rs

@@ -391,8 +391,8 @@ pub fn find_interpreter(
             // argument.
             if target.is_windows() {
                 if let Some(manual_base_prefix) = std::env::var_os("PYO3_CROSS_LIB_DIR") {
-                    // PYO3_CROSS_LIB_DIR equals base_prefix when cross compiling,
-                    // so we fake a python interpreter matching it
+                    // PYO3_CROSS_LIB_DIR should point to the `libs` directory inside base_prefix
+                    // when cross compiling, so we fake a python interpreter matching it
                     println!("⚠ Cross-compiling is poorly supported");
                     Ok(vec![PythonInterpreter {
                         major: *major as usize,
@@ -403,7 +403,7 @@ pub fn find_interpreter(
                         ext_suffix: Some(".pyd".to_string()),
                         interpreter_kind: InterpreterKind::CPython,
                         abi_tag: None,
-                        base_prefix: PathBuf::from(manual_base_prefix),
+                        libs_dir: PathBuf::from(manual_base_prefix),
                     }])
                 } else {
                     let interpreter = find_single_python_interpreter(

src/compile.rs

@@ -66,8 +66,7 @@ pub fn compile(
         if context.target.is_windows() {
             let python_interpreter = python_interpreter
                 .expect("Must have a python interpreter for building abi3 on windows");
-            pythonxy_lib_folder =
-                format!("native={}\\libs", python_interpreter.base_prefix.display());
+            pythonxy_lib_folder = format!("native={}", python_interpreter.libs_dir.display());
             rustc_args.extend(&["-L", &pythonxy_lib_folder]);
         }
     }

src/python_interpreter.rs

@@ -292,7 +292,7 @@ pub struct PythonInterpreter {
     /// Note that this always `None` on windows
     pub abi_tag: Option<String>,
     /// We need this value for windows abi3 linking
-    pub base_prefix: PathBuf,
+    pub libs_dir: PathBuf,
 }
 
 /// Returns the abiflags that are assembled through the message, with some
@@ -535,7 +535,7 @@ impl PythonInterpreter {
             ext_suffix: message.ext_suffix,
             interpreter_kind: interpreter,
             abi_tag: message.abi_tag,
-            base_prefix: PathBuf::from(message.base_prefix),
+            libs_dir: PathBuf::from(message.base_prefix).join("libs"),
         }))
     }
 

test-crates/pyo3-pure/Cargo.toml

@@ -10,7 +10,7 @@ edition = "2018"
 get_42 = "pyo3_pure:DummyClass.get_42"
 
 [dependencies]
-pyo3 = { version ="0.13.1", features = ["abi3-py36", "extension-module"] }
+pyo3 = { version = "0.13.1", features = ["abi3-py36", "extension-module"] }
 
 [lib]
 name = "pyo3_pure"