Merge pull request #7777 from sinscary/fix_#7249

Raise error if --user and --target arguments are used together

news/7249.feature

@@ -0,0 +1 @@
+Raise error if --user and --target are used together in pip install

src/pip/_internal/commands/install.py

@@ -237,6 +237,9 @@ class InstallCommand(RequirementCommand):
     @with_cleanup
     def run(self, options, args):
         # type: (Values, List[Any]) -> int
+        if options.use_user_site and options.target_dir is not None:
+            raise CommandError("Can not combine '--user' and '--target'")
+
         cmdoptions.check_install_build_global(options)
         upgrade_strategy = "to-satisfy-only"
         if options.upgrade:

tests/functional/test_install.py

@@ -847,6 +847,27 @@ def test_install_package_with_target(script):
     assert singlemodule_py in result.files_updated, str(result)
 
 
+def test_install_package_to_usersite_with_target_must_fail(script):
+    """
+    Test that installing package to usersite with target
+    must raise error
+    """
+    target_dir = script.scratch_path / 'target'
+    result = script.pip_install_local(
+        '--user', '-t', target_dir, "simple==1.0", expect_error=True
+    )
+    assert "Can not combine '--user' and '--target'" in result.stderr, (
+        str(result)
+    )
+
+    result = script.pip_install_local(
+        '--user', '--target', target_dir, "simple==1.0", expect_error=True
+    )
+    assert "Can not combine '--user' and '--target'" in result.stderr, (
+        str(result)
+    )
+
+
 def test_install_nonlocal_compatible_wheel(script, data):
     target_dir = script.scratch_path / 'target'