Mark TestSubmodule.test_rename xfail on Windows

The test fails when attempting to evaluate the expression:

    sm.move(new_path).name

as part of the assertion:

    assert sm.move(new_path).name == new_path

But it is the call to sm.move that fails, not the assertion itself.
The condition is never evaluated, because the subexpression raises
PermissionError. Details are in the xfail reason string.

This test_submodule.TestSubmodule.test_rename method should not be
confused with test_config.TestBase.test_rename, which passes on all
platforms.

Surprisingly, on CI, this has XPASS status on Python 3.7. Somehow
the test is passing, but only on CI, and only on 3.7. This should
be investigated. The xfail condition could be adjusted, but locally
on Windows I find it to fail, even on 3.7.9 (the exact version the
CI test runner reports it is using for Python 3.7). If the xfail
condition cannot be made more accurate, a comment could be added.

Author: EliahKagan

test/test_submodule.py

@@ -949,6 +949,17 @@ def test_remove_norefs(self, rwdir):
         sm.remove()
         assert not sm.exists()
 
+    @pytest.mark.xfail(
+        os.name == "nt",
+        reason=(
+            "The sm.move call fails. Submodule.move calls os.renames, which raises:\n"
+            "PermissionError: [WinError 32] "
+            "The process cannot access the file because it is being used by another process: "
+            R"'C:\Users\ek\AppData\Local\Temp\test_renamekkbznwjp\parent\mymodules\myname' "
+            R"-> 'C:\Users\ek\AppData\Local\Temp\test_renamekkbznwjp\parent\renamed\myname'"
+        ),
+        raises=PermissionError,
+    )
     @with_rw_directory
     def test_rename(self, rwdir):
         parent = git.Repo.init(osp.join(rwdir, "parent"))