Allow missing `Scripts` directory (#16206)

With the new Python install manager, the `Scripts` directory reported by
Python may not exist.

See https://github.com/astral-sh/uv/pull/16205 for a failing CI run:
https://github.com/astral-sh/uv/actions/runs/18377230241/job/52354460636?pr=16205#step:4:15

Fixes https://github.com/astral-sh/uv/issues/16204

.github/workflows/ci.yml

@@ -1289,6 +1289,30 @@ jobs:
           ./uv run python -c ""
           ./uv run -p 3.13 python -c ""
 
+  integration-test-windows-python-install-manager:
+    timeout-minutes: 10
+    needs: build-binary-windows-x86_64
+    name: "integration test | windows python install manager"
+    runs-on: windows-latest
+
+    steps:
+      - name: "Download binary"
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        with:
+          name: uv-windows-x86_64-${{ github.sha }}
+
+      - name: "Install Python via Python Install manager"
+        run: |
+          # https://www.python.org/downloads/release/pymanager-250/
+          winget install --accept-package-agreements --accept-source-agreements 9NQ7512CXL7T
+          # Call Python Install Manager's py.exe by full path to avoid legacy py.exe
+          & "$env:LOCALAPPDATA\Microsoft\WindowsApps\py.exe" install 3.14
+
+      # https://github.com/astral-sh/uv/issues/16204
+      - name: "Check temporary environment creation"
+        run: |
+          ./uv run -p $env:LOCALAPPDATA\Python\pythoncore-3.14-64\python.exe --with numpy python -c "import sys; print(sys.executable)"
+
   integration-test-pypy-linux:
     timeout-minutes: 10
     needs: build-binary-linux-libc

crates/uv/src/commands/project/run.rs

@@ -2,6 +2,7 @@ use std::borrow::Cow;
 use std::env::VarError;
 use std::ffi::OsString;
 use std::fmt::Write;
+use std::io;
 use std::io::Read;
 use std::path::{Path, PathBuf};
 
@@ -1099,7 +1100,12 @@ hint: If you are running a script with `{}` in the shebang, you may need to incl
                 // Copy each entrypoint from the base environments to the ephemeral environment,
                 // updating the Python executable target to ensure they run in the ephemeral
                 // environment.
-                for entry in fs_err::read_dir(interpreter.scripts())? {
+                let scripts = match fs_err::read_dir(interpreter.scripts()) {
+                    Ok(scripts) => scripts,
+                    Err(err) if err.kind() == io::ErrorKind::NotFound => continue,
+                    Err(err) => return Err(err.into()),
+                };
+                for entry in scripts {
                     let entry = entry?;
                     if !entry.file_type()?.is_file() {
                         continue;
@@ -1200,23 +1206,13 @@ hint: If you are running a script with `{}` in the shebang, you may need to incl
             "Provide a command or script to invoke with `uv run <command>` or `uv run <script>.py`.\n"
         )?;
 
-        #[allow(clippy::map_identity)]
+        let scripts = match fs_err::read_dir(interpreter.scripts()) {
-        let commands = interpreter
+            Ok(scripts) => scripts.into_iter().collect::<Result<Vec<_>, _>>()?,
-            .scripts()
+            Err(err) if err.kind() == io::ErrorKind::NotFound => Vec::new(),
-            .read_dir()
+            Err(err) => return Err(err.into()),
-            .ok()
+        };
-            .into_iter()
+
-            .flatten()
+        let commands = scripts
-            .map(|entry| match entry {
-                Ok(entry) => Ok(entry),
-                Err(err) => {
-                    // If we can't read the entry, fail.
-                    // This could be a symptom of a more serious problem.
-                    warn!("Failed to read entry: {}", err);
-                    Err(err)
-                }
-            })
-            .collect::<Result<Vec<_>, _>>()?
             .into_iter()
             .filter(|entry| {
                 entry
@@ -1226,7 +1222,7 @@ hint: If you are running a script with `{}` in the shebang, you may need to incl
             .map(|entry| entry.path())
             .filter(|path| is_executable(path))
             .map(|path| {
-                if cfg!(windows)
+                let path = if cfg!(windows)
                     && path
                         .extension()
                         .is_some_and(|exe| exe == std::env::consts::EXE_EXTENSION)
@@ -1235,9 +1231,8 @@ hint: If you are running a script with `{}` in the shebang, you may need to incl
                     path.with_extension("")
                 } else {
                     path
-                }
+                };
-            })
+
-            .map(|path| {
                 path.file_name()
                     .unwrap_or_default()
                     .to_string_lossy()