Expand PDM's ~ from USERPROFILE on Windows

PDM expands a `~` in global_project.path or python.install_root with
Python's expanduser, which uses USERPROFILE on Windows and ignores
HOME. Under Git Bash, HOME is an MSYS path, so the relocated global
project or interpreter root was looked for in the wrong place.

Assisted-by: Claude Code:claude-opus-5-5

Author: claude

crates/socket-patch-core/src/crawlers/python_crawler.rs

@@ -1703,7 +1703,15 @@ async fn pdm_global_site_packages(home_dir: &Path) -> Vec<PathBuf> {
     let mut projects = Vec::new();
     let mut install_roots = Vec::new();
     let mut venv_roots = Vec::new();
-    let var = |name: &str| std::env::var(name).ok();
+    // PDM expands `~` with Python's `expanduser`, which reads USERPROFILE
+    // on Windows and ignores HOME there (Python 3.8+), so a Git Bash HOME
+    // must not decide where a relocated setting points.
+    let var = |name: &str| {
+        if cfg!(windows) && name == "HOME" {
+            return None;
+        }
+        std::env::var(name).ok()
+    };
     for file in &config_files {
         let Ok(text) = read_regular_to_string(file).await else {
             continue;

crates/socket-patch-core/tests/crawler_python_e2e.rs

@@ -928,11 +928,17 @@ async fn get_global_python_site_packages_discovers_pdm_managed_interpreters() {
 
 /// `global_project.path` and `python.install_root` in PDM's global
 /// config (`$PDM_CONFIG_FILE` here) relocate both, with `~` expanded the
-/// way PDM's `expanduser` does (#451).
+/// way PDM's `expanduser` does: from USERPROFILE on Windows, where a Git
+/// Bash HOME is ignored, and from HOME elsewhere (#451).
 #[tokio::test]
 #[serial]
 async fn get_global_python_site_packages_follows_pdm_config_overrides() {
     let tmp = tempfile::tempdir().unwrap();
+    let home = if cfg!(windows) {
+        tmp.path().join("msys-home")
+    } else {
+        tmp.path().to_path_buf()
+    };
     let config_file = tmp.path().join("pdm-config.toml");
     tokio::fs::write(
         &config_file,
@@ -943,8 +949,11 @@ async fn get_global_python_site_packages_follows_pdm_config_overrides() {
     let project_sp = stage_env(&tmp.path().join("gp").join(".venv")).await;
     let python_sp = stage_env(&tmp.path().join("pyroot").join("cpython@3.12.14")).await;
 
-    let result =
-        global_site_packages_with_vars(tmp.path(), &[("PDM_CONFIG_FILE", &config_file)]).await;
+    let mut vars: Vec<(&str, &Path)> = vec![("PDM_CONFIG_FILE", &config_file)];
+    if cfg!(windows) {
+        vars.push(("USERPROFILE", tmp.path()));
+    }
+    let result = global_site_packages_with_vars(&home, &vars).await;
     assert_surfaces(
         &result,
         &project_sp,