Remove the ability to uninstall distutils installed projects

news/2386.removal

@@ -0,0 +1,5 @@
+Removed support for uninstalling projects which have been installed using
+distutils. distutils installed projects do not include metadata indicating
+what files belong to that install and thus it is impossible to *actually*
+install them rather than just remove the metadata saying they've been installed
+while leaving all of the actual files behind.

pip/req/req_uninstall.py

@@ -21,7 +21,6 @@
     egg_link_path, FakeFile,
     renames, normalize_path, dist_is_local,
 )
-from pip.utils.deprecation import RemovedInPip10Warning
 from pip.utils.logging import indent_log
 
 
@@ -274,15 +273,13 @@ def from_dist(cls, dist):
                     paths_to_remove.add(path + '.pyo')
 
         elif distutils_egg_info:
-            warnings.warn(
-                "Uninstalling a distutils installed project ({0}) has been "
-                "deprecated and will be removed in a future version. This is "
-                "due to the fact that uninstalling a distutils project will "
-                "only partially uninstall the project.".format(
-                    dist.project_name),
-                RemovedInPip10Warning,
+            raise UninstallationError(
+                "Cannot uninstall {!r}. It is a distutils installed project "
+                "and thus we cannot accurately determine which files belong "
+                "to it which would lead to only a partial uninstall.".format(
+                    dist.project_name,
+                )
             )
-            paths_to_remove.add(distutils_egg_info)
 
         elif dist.location.endswith('.egg'):
             # package installed by easy_install

tests/functional/test_uninstall.py

@@ -52,10 +52,13 @@ def test_simple_uninstall_distutils(script):
     result = script.pip('list', '--format=json')
     assert {"name": "distutils-install", "version": "0.1"} \
         in json.loads(result.stdout)
-    script.pip('uninstall', 'distutils_install', '-y', expect_stderr=True)
-    result2 = script.pip('list', '--format=json')
-    assert {"name": "distutils-install", "version": "0.1"} \
-        not in json.loads(result2.stdout)
+    result = script.pip('uninstall', 'distutils_install', '-y',
+                        expect_stderr=True, expect_error=True)
+    assert result.stderr.strip() == (
+        "Cannot uninstall 'distutils-install'. It is a distutils installed "
+        "project and thus we cannot accurately determine which files belong "
+        "to it which would lead to only a partial uninstall."
+    )
 
 
 @pytest.mark.network