Support Pyodide interpreter in windows (#17658)

## Summary

This adds Pyodide interpreter support in windows environment. In Pyodide
0.29.2, we made some enhancements to run Pyodide CLI in windows. This PR
relaxes a check that was disabling `uv pip` in Windows + Pyodide and
adds integration test.

## Test Plan

Added integration test, also tested locally by running

```
uv python install cpython-3.13.2-emscripten-wasm32-musl
uv venv venv-pyodide -p cpython-3.13.2-emscripten-wasm32-musl
call venv-pyodide\Scripts\activate
uv pip install packaging
python -c "import packaging"
```

.github/workflows/test-integration.yml

@@ -615,6 +615,43 @@ jobs:
           ./uv pip install packaging
           python -c 'import packaging'
 
+  integration-test-pyodide-windows:
+    name: "pyodide on windows"
+    timeout-minutes: 10
+    runs-on: windows-latest
+    # Github Actions Windows runner uses D drive as pwd.
+    # Pyodide CLI has an issue running cross-drive,
+    # So ensure that cache and Pyodide paths are on D drive as well.
+    env:
+      UV_CACHE_DIR: D:\uv-cache
+      PYODIDE_XBUILDENV_PATH: D:\pyodide-xbuildenv
+    steps:
+      - name: "Download binary"
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        with:
+          name: uv-windows-x86_64-${{ inputs.sha }}
+
+      - name: "Create a native virtual environment"
+        run: |
+          .\uv.exe venv venv-native -p 3.13
+          .\uv.exe pip install -p venv-native\Scripts\python.exe pyodide-build==0.31.1 pip
+
+      - name: "Install Pyodide interpreter"
+        run: |
+          & .\venv-native\Scripts\Activate.ps1
+          pyodide xbuildenv install 0.29.2
+          $env:PYODIDE_PYTHON = pyodide config get interpreter
+          $env:PYODIDE_INDEX = pyodide config get package_index
+          echo "PYODIDE_PYTHON=$env:PYODIDE_PYTHON" >> $env:GITHUB_ENV
+          echo "PYODIDE_INDEX=$env:PYODIDE_INDEX" >> $env:GITHUB_ENV
+
+      - name: "Create Pyodide virtual environment"
+        run: |
+          .\uv.exe venv -p $env:PYODIDE_PYTHON venv-pyodide
+          & .\venv-pyodide\Scripts\Activate.ps1
+          .\uv.exe pip install --extra-index-url=$env:PYODIDE_INDEX --no-build numpy
+          python -c 'import numpy'
+
   integration-test-github-actions:
     name: "github actions"
     timeout-minutes: 10

Cargo.lock

@@ -7182,6 +7182,7 @@ dependencies = [
  "tracing",
  "uv-console",
  "uv-fs",
+ "uv-platform-tags",
  "uv-preview",
  "uv-pypi-types",
  "uv-python",

crates/uv-platform/src/os.rs

@@ -30,12 +30,9 @@ impl Os {
 
     /// Whether this OS can run the other OS.
     pub fn supports(&self, other: Self) -> bool {
-        // Emscripten cannot run on Windows, but all other OSes can run Emscripten.
+        // Emscripten can run on any OS
         if other.is_emscripten() {
-            return !self.is_windows();
-        }
-        if self.is_windows() && other.is_emscripten() {
-            return false;
+            return true;
         }
 
         // Otherwise, we require an exact match

crates/uv-virtualenv/Cargo.toml

@@ -20,6 +20,7 @@ workspace = true
 [dependencies]
 uv-console = { workspace = true }
 uv-fs = { workspace = true }
+uv-platform-tags = { workspace = true }
 uv-preview = { workspace = true }
 uv-pypi-types = { workspace = true }
 uv-python = { workspace = true }

crates/uv-virtualenv/src/virtualenv.rs

@@ -12,6 +12,7 @@ use owo_colors::OwoColorize;
 use tracing::{debug, trace};
 
 use uv_fs::{CWD, Simplified, cachedir};
+use uv_platform_tags::Os;
 use uv_preview::Preview;
 use uv_pypi_types::Scheme;
 use uv_python::managed::{PythonMinorVersionLink, create_link_to_executable};
@@ -314,6 +315,12 @@ pub(crate) fn create(
                 create_link_to_executable(targetwt.as_path(), &executable_target)
                     .map_err(Error::Python)?;
             }
+        } else if matches!(interpreter.platform().os(), Os::Pyodide { .. }) {
+            // For Pyodide, link only `python.exe`.
+            // This should not be copied as `python.exe` is a wrapper that launches Pyodide.
+            let target = scripts.join(WindowsExecutable::Python.exe(interpreter));
+            create_link_to_executable(target.as_path(), &executable_target)
+                .map_err(Error::Python)?;
         } else {
             // Always copy `python.exe`.
             copy_launcher_windows(