This test incorrectly assumes that the root user is always available.
However, in the build environment, the root user is not available.
Note that because the original file distributed in the release on PyPi
has lines ending in CRLF, those are retained in the diff below.

--- a/pyfakefs/tests/fake_filesystem_test.py	1969-12-31 16:00:00.000000000 -0800
+++ b/pyfakefs/tests/fake_filesystem_test.py	1969-12-31 16:00:00.000000000 -0800
@@ -1021,15 +1021,6 @@
             self.assertEqual(self.path.expanduser('~'),
                              self.os.environ['HOME'].replace('/', '!'))
 
-    @unittest.skipIf(TestCase.is_windows or TestCase.is_cygwin,
-                     'only tested on unix systems')
-    def test_expand_root(self):
-        if sys.platform == 'darwin':
-            roothome = '!var!root'
-        else:
-            roothome = '!root'
-        self.assertEqual(self.path.expanduser('~root'), roothome)
-
     def test_getsize_path_nonexistent(self):
         file_path = 'foo!bar!baz'
         self.assertRaises(os.error, self.path.getsize, file_path)
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<div class='path'>path: <a href='/guix/log/?id=aef51732226c38a919c8845d649e9bb05433ed03'>root</a>/<a href='/guix/log/tests?id=aef51732226c38a919c8845d649e9bb05433ed03'>tests</a>/<a href='/guix/log/tests/ed25519.key?id=aef51732226c38a919c8845d649e9bb05433ed03'>ed25519.key</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/ed25519.key?id=aef51732226c38a919c8845d649e9bb05433ed03&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-05-04 09:56:12 +0200'>2020-05-04</span></td><td><a href='/guix/commit/tests/ed25519.key?id=43408e304ffb1149f35cb539b40d673d567c9116'>Add (guix openpgp).</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/openpgp.scm, tests/openpgp.scm, tests/civodul.key,
tests/dsa.key, tests/ed25519.key, tests/rsa.key,
tests/ed25519.sec: New files.
* Makefile.am (MODULES): Add guix/openpgp.scm.
(SCM_TESTS): Add tests/openpgp.scm.
(EXTRA_DIST): Add tests/*.key and tests/ed25519.sec.
</span></span></td><td>Ludovic Courtès</td></tr>