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Merged
youknowone merged 1 commit into from
Jan 19, 2026
Merged

Add sys._stdlib_dir #6798

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5 changes: 3 additions & 2 deletions Lib/test/test_importlib/resources/test_files.py
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Expand Up @@ -52,7 +52,7 @@ class OpenDiskTests(FilesTests, unittest.TestCase):
def setUp(self):
self.data = data01

@unittest.expectedFailureIfWindows("TODO: RUSTPYTHON")
@unittest.expectedFailureIfWindows("TODO: RUSTPYTHON, line ending issue")
def test_read_bytes(self):
super().test_read_bytes()

Expand All @@ -67,10 +67,11 @@ def setUp(self):

self.data = namespacedata01

@unittest.expectedFailureIfWindows("TODO: RUSTPYTHON")
@unittest.expectedFailureIfWindows("TODO: RUSTPYTHON, line ending issue")
def test_read_bytes(self):
super().test_read_bytes()


class SiteDir:
def setUp(self):
self.fixtures = contextlib.ExitStack()
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1 change: 0 additions & 1 deletion Lib/test/test_sys.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1310,7 +1310,6 @@ def test_module_names(self):
for name in sys.stdlib_module_names:
self.assertIsInstance(name, str)

@unittest.expectedFailure # TODO: RUSTPYTHON; AttributeError: module 'sys' has no attribute '_stdlib_dir'
def test_stdlib_dir(self):
os = import_helper.import_fresh_module('os')
marker = getattr(os, '__file__', None)
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28 changes: 19 additions & 9 deletions crates/pylib/build.rs
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Expand Up @@ -11,15 +11,25 @@ fn main() {
process_python_libs("./Lib/**/*");
}

if cfg!(windows)
&& let Ok(real_path) = std::fs::read_to_string("Lib")
{
let canonicalized_path = std::fs::canonicalize(real_path)
.expect("failed to resolve RUSTPYTHONPATH during build time");
// Strip the extended path prefix (\\?\) that canonicalize adds on Windows
let path_str = canonicalized_path.to_str().unwrap();
let path_str = path_str.strip_prefix(r"\\?\").unwrap_or(path_str);
println!("cargo:rustc-env=win_lib_path={path_str}");
if cfg!(windows) {
// On Windows, the Lib entry can be either:
// 1. A text file containing the relative path (git without symlink support)
// 2. A proper symlink (git with symlink support)
// We handle both cases to resolve to the actual Lib directory.
let lib_path = if let Ok(real_path) = std::fs::read_to_string("Lib") {
// Case 1: Text file containing relative path
std::path::PathBuf::from(real_path.trim())
} else {
// Case 2: Symlink or directory - canonicalize directly
std::path::PathBuf::from("Lib")
};

if let Ok(canonicalized_path) = std::fs::canonicalize(&lib_path) {
// Strip the extended path prefix (\\?\) that canonicalize adds on Windows
let path_str = canonicalized_path.to_str().unwrap();
let path_str = path_str.strip_prefix(r"\\?\").unwrap_or(path_str);
println!("cargo:rustc-env=win_lib_path={path_str}");
Comment on lines +14 to +31
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@coderabbitai coderabbitai bot Jan 19, 2026

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⚠️ Potential issue | 🟠 Major

Avoid panic on non‑UTF‑8 Windows paths.
to_str().unwrap() can panic on valid Windows paths containing non‑UTF‑8 sequences, breaking the build. Prefer a lossy conversion and consider warning when canonicalization fails so missing win_lib_path isn’t silent.

🔧 Proposed safer emission 
-        if let Ok(canonicalized_path) = std::fs::canonicalize(&lib_path) {
-            // Strip the extended path prefix (\\?\) that canonicalize adds on Windows
-            let path_str = canonicalized_path.to_str().unwrap();
-            let path_str = path_str.strip_prefix(r"\\?\").unwrap_or(path_str);
-            println!("cargo:rustc-env=win_lib_path={path_str}");
-        }
+        if let Ok(canonicalized_path) = std::fs::canonicalize(&lib_path) {
+            // Strip the extended path prefix (\\?\) that canonicalize adds on Windows
+            let path_str = canonicalized_path.to_string_lossy();
+            let path_str = path_str.strip_prefix(r"\\?\").unwrap_or(&path_str);
+            println!("cargo:rustc-env=win_lib_path={path_str}");
+        } else {
+            println!("cargo:warning=failed to canonicalize Lib path: {:?}", lib_path);
+        }
🤖 Prompt for AI Agents 
In `@crates/pylib/build.rs` around lines 14 - 31, The build script currently calls
canonicalize(...).to_str().unwrap(), which can panic on non‑UTF‑8 Windows paths;
change the emission to use a lossy conversion from the canonicalized Path (e.g.,
Path::to_string_lossy on the value returned by std::fs::canonicalize(&lib_path))
and print that into the cargo:rustc-env=win_lib_path value, and if
std::fs::canonicalize(&lib_path) returns an Err emit a visible build warning via
println!("cargo:warning=...") instead of silently skipping so missing
win_lib_path is obvious; update the code paths referencing canonicalized_path
and to_str().unwrap() accordingly.

}
}
}

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19 changes: 19 additions & 0 deletions crates/vm/src/getpath.rs
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Expand Up @@ -174,6 +174,9 @@ pub fn init_path_config(settings: &Settings) -> Paths {
paths.module_search_paths =
build_module_search_paths(settings, &paths.prefix, &paths.exec_prefix);

// Step 9: Calculate stdlib_dir
paths.stdlib_dir = calculate_stdlib_dir(&paths.prefix);

paths
}

Expand Down Expand Up @@ -301,6 +304,22 @@ fn calculate_base_executable(executable: Option<&PathBuf>, home_dir: &Option<Pat
.unwrap_or_default()
}

/// Calculate stdlib_dir (sys._stdlib_dir)
/// Returns None if the stdlib directory doesn't exist
fn calculate_stdlib_dir(prefix: &str) -> Option<String> {
#[cfg(not(windows))]
let stdlib_dir = PathBuf::from(prefix).join(platform::stdlib_subdir());

#[cfg(windows)]
let stdlib_dir = PathBuf::from(prefix).join(platform::STDLIB_SUBDIR);

if stdlib_dir.is_dir() {
Some(stdlib_dir.to_string_lossy().into_owned())
} else {
None
}
}

/// Build the complete module_search_paths (sys.path)
fn build_module_search_paths(settings: &Settings, prefix: &str, exec_prefix: &str) -> Vec<String> {
let mut paths = Vec::new();
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4 changes: 4 additions & 0 deletions crates/vm/src/stdlib/sys.rs
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Expand Up @@ -148,6 +148,10 @@ mod sys {
fn platlibdir(_vm: &VirtualMachine) -> &'static str {
option_env!("RUSTPYTHON_PLATLIBDIR").unwrap_or("lib")
}
#[pyattr]
fn _stdlib_dir(vm: &VirtualMachine) -> PyObjectRef {
vm.state.config.paths.stdlib_dir.clone().to_pyobject(vm)
}

// alphabetical order with segments of pyattr and others

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2 changes: 2 additions & 0 deletions crates/vm/src/vm/setting.rs
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Expand Up @@ -16,6 +16,8 @@ pub struct Paths {
pub exec_prefix: String,
/// sys.base_exec_prefix
pub base_exec_prefix: String,
/// sys._stdlib_dir
pub stdlib_dir: Option<String>,
/// Computed module_search_paths (complete sys.path)
pub module_search_paths: Vec<String>,
}
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20 changes: 10 additions & 10 deletions src/interpreter.rs
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Expand Up @@ -113,18 +113,13 @@ pub fn init_stdlib(vm: &mut VirtualMachine) {
/// Setup frozen standard library (compiled into the binary)
#[cfg(all(feature = "stdlib", feature = "freeze-stdlib"))]
fn setup_frozen_stdlib(vm: &mut VirtualMachine) {
use rustpython_vm::common::rc::PyRc;

vm.add_frozen(rustpython_pylib::FROZEN_STDLIB);

// FIXME: Remove this hack once sys._stdlib_dir is properly implemented
// or _frozen_importlib doesn't depend on it anymore.
assert!(vm.sys_module.get_attr("_stdlib_dir", vm).is_err());
vm.sys_module
.set_attr(
"_stdlib_dir",
vm.new_pyobj(rustpython_pylib::LIB_PATH.to_owned()),
vm,
)
.unwrap();
// Set stdlib_dir to the frozen stdlib path
let state = PyRc::get_mut(&mut vm.state).unwrap();
state.config.paths.stdlib_dir = Some(rustpython_pylib::LIB_PATH.to_owned());
}

/// Setup dynamic standard library loading from filesystem
Expand All @@ -135,6 +130,11 @@ fn setup_dynamic_stdlib(vm: &mut VirtualMachine) {
let state = PyRc::get_mut(&mut vm.state).unwrap();
let paths = collect_stdlib_paths();

// Set stdlib_dir to the first stdlib path if available
if let Some(first_path) = paths.first() {
state.config.paths.stdlib_dir = Some(first_path.clone());
}

// Insert at the beginning so stdlib comes before user paths
for path in paths.into_iter().rev() {
state.config.paths.module_search_paths.insert(0, path);
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