On this machine, C:\Users is a junction to D:\Users .

Sample failure:

Running Release|x64 interpreter...
....FFF........s...s..s.s.s................s......FF..............ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss.........................................................................................................................................................................FFF........s...s..s.s.s................s......FF...........
======================================================================
FAIL: test_complex_symlinks_absolute (__main__.PathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2027, in test_complex_symlinks_absolute
    self._check_complex_symlinks(BASE)
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_complex_symlinks_relative (__main__.PathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2031, in test_complex_symlinks_relative
    self._check_complex_symlinks('.')
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_complex_symlinks_relative_dot_dot (__main__.PathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2035, in test_complex_symlinks_relative_dot_dot
    self._check_complex_symlinks(os.path.join('dirA', '..'))
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_resolve_common (__main__.PathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 1491, in test_resolve_common
    os.path.join(BASE, 'foo'))
AssertionError: 'D:\\Users\\Ivan\\Documents\\cpython_all\\@test_2376_tmp\\foo' != 'C:\\Users\\Ivan\\Documents\\cpython_all\\@test_2376_tmp\\foo'
- D:\Users\Ivan\Documents\cpython_all\@test_2376_tmp\foo
? ^
+ C:\Users\Ivan\Documents\cpython_all\@test_2376_tmp\foo
? ^


======================================================================
FAIL: test_resolve_dot (__main__.PathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 1550, in test_resolve_dot
    self.assertEqual(q.resolve(strict=True), p)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_complex_symlinks_absolute (__main__.WindowsPathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2027, in test_complex_symlinks_absolute
    self._check_complex_symlinks(BASE)
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_complex_symlinks_relative (__main__.WindowsPathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2031, in test_complex_symlinks_relative
    self._check_complex_symlinks('.')
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_complex_symlinks_relative_dot_dot (__main__.WindowsPathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 2035, in test_complex_symlinks_relative_dot_dot
    self._check_complex_symlinks(os.path.join('dirA', '..'))
  File "Lib\test\test_pathlib.py", line 1994, in _check_complex_symlinks
    self.assertEqual(p, P)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

======================================================================
FAIL: test_resolve_common (__main__.WindowsPathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 1491, in test_resolve_common
    os.path.join(BASE, 'foo'))
AssertionError: 'D:\\Users\\Ivan\\Documents\\cpython_all\\@test_2376_tmp\\foo' != 'C:\\Users\\Ivan\\Documents\\cpython_all\\@test_2376_tmp\\foo'
- D:\Users\Ivan\Documents\cpython_all\@test_2376_tmp\foo
? ^
+ C:\Users\Ivan\Documents\cpython_all\@test_2376_tmp\foo
? ^


======================================================================
FAIL: test_resolve_dot (__main__.WindowsPathTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib\test\test_pathlib.py", line 1550, in test_resolve_dot
    self.assertEqual(q.resolve(strict=True), p)
AssertionError: WindowsPath('D:/Users/Ivan/Documents/cpython_all/@test_2376_tmp') != WindowsPath('C:/Users/Ivan/Documents/cpython_all/@test_2376_tmp')

----------------------------------------------------------------------
Ran 394 tests in 2.215s

FAILED (failures=10, skipped=112)