Disable the distutils setuptools shim during interpreter query (#10819)

Addresses
https://github.com/astral-sh/uv/issues/4204#issuecomment-2604983670

Original context in https://github.com/astral-sh/uv/issues/2302

.github/workflows/ci.yml

@@ -691,17 +691,9 @@ jobs:
       - name: "Prepare binary"
         run: chmod +x ./uv
 
-      - name: "Create a virtual environment"
+      - name: "Check missing distutils"
         run: |
-          ./uv venv -p 3.9 --python-preference only-system
+          ./uv venv -p 3.9 --python-preference only-system -v 2>&1 | tee log.txt || true
-
-      - name: "Check version"
-        run: |
-          .venv/bin/python --version
-
-      - name: "Check install missing distutils"
-        run: |
-          ./uv pip install -v anyio 2>&1 | tee log.txt || true
           # We should report that distutils is missing
           grep 'Python installation is missing `distutils`' log.txt
 
@@ -709,10 +701,17 @@ jobs:
         run: |
           sudo apt-get install python3.9-distutils
 
+      - name: "Create a virtualenv"
+        run: |
+          ./uv venv -p 3.9 --python-preference only-system -v
+
+      - name: "Check version"
+        run: |
+          .venv/bin/python --version
+
       - name: "Check install"
         run: |
           ./uv pip install -v anyio
-          # Now the install should succeed
 
   integration-test-free-threaded-linux:
     timeout-minutes: 5

crates/uv-python/python/get_interpreter_info.py

@@ -176,6 +176,9 @@ def get_virtualenv():
             "data": expand_path(sysconfig_paths["data"]),
         }
     else:
+        # Use distutils primarily because that's what pip does.
+        # https://github.com/pypa/pip/blob/ae5fff36b0aad6e5e0037884927eaa29163c0611/src/pip/_internal/locations/__init__.py#L249
+
         # Disable the use of the setuptools shim, if it's injected. Per pip:
         #
         # > If pip's going to use distutils, it should not be using the copy that setuptools
@@ -189,8 +192,6 @@ def get_virtualenv():
         except (ImportError, AttributeError):
             pass
 
-        # Use distutils primarily because that's what pip does.
-        # https://github.com/pypa/pip/blob/ae5fff36b0aad6e5e0037884927eaa29163c0611/src/pip/_internal/locations/__init__.py#L249
         import warnings
 
         with warnings.catch_warnings():  # disable warning for PEP-632
@@ -337,19 +338,6 @@ def get_scheme(use_sysconfig_scheme: bool):
         Based on (with default arguments):
             https://github.com/pypa/pip/blob/ae5fff36b0aad6e5e0037884927eaa29163c0611/src/pip/_internal/locations/_distutils.py#L115
         """
-        # Disable the use of the setuptools shim, if it's injected. Per pip:
-        #
-        # > If pip's going to use distutils, it should not be using the copy that setuptools
-        # > might have injected into the environment. This is done by removing the injected
-        # > shim, if it's injected.
-        #
-        # > See https://github.com/pypa/pip/issues/8761 for the original discussion and
-        # > rationale for why this is done within pip.
-        try:
-            __import__("_distutils_hack").remove_shim()
-        except (ImportError, AttributeError):
-            pass
-
         import warnings
 
         with warnings.catch_warnings():  # disable warning for PEP-632
@@ -575,6 +563,19 @@ def main() -> None:
     # If we're not using sysconfig, make sure distutils is available.
     if not use_sysconfig_scheme:
         try:
+            # Disable the use of the setuptools shim, if it's injected. Per pip:
+            #
+            # > If pip's going to use distutils, it should not be using the copy that setuptools
+            # > might have injected into the environment. This is done by removing the injected
+            # > shim, if it's injected.
+            #
+            # > See https://github.com/pypa/pip/issues/8761 for the original discussion and
+            # > rationale for why this is done within pip.
+            try:
+                __import__("_distutils_hack").remove_shim()
+            except (ImportError, AttributeError):
+                pass
+            
             import distutils.dist
         except ImportError:
             # We require distutils, but it's not installed; this is fairly