terminal: write_fspath_result: work around py bug

src/_pytest/terminal.py

@@ -261,7 +261,9 @@ def hasopt(self, char):
 
     def write_fspath_result(self, nodeid, res, **markup):
         fspath = self.config.rootdir.join(nodeid.split("::")[0])
-        if fspath != self.currentfspath:
+        # NOTE: explicitly check for None to work around py bug, and for less
+        # overhead in general (https://github.com/pytest-dev/py/pull/207).
+        if self.currentfspath is None or fspath != self.currentfspath:
             if self.currentfspath is not None and self._show_progress_info:
                 self._write_progress_information_filling_space()
             self.currentfspath = fspath

testing/test_assertrewrite.py

@@ -1308,10 +1308,17 @@ def test_simple_failure():
     @pytest.mark.skipif(
         sys.platform.startswith("win32"), reason="cannot remove cwd on Windows"
     )
-    def test_cwd_changed(self, testdir):
+    def test_cwd_changed(self, testdir, monkeypatch):
+        # Setup conditions for py's fspath trying to import pathlib on py34
+        # always (previously triggered via xdist only).
+        # Ref: https://github.com/pytest-dev/py/pull/207
+        monkeypatch.setattr(sys, "path", [""] + sys.path)
+        if "pathlib" in sys.modules:
+            del sys.modules["pathlib"]
+
         testdir.makepyfile(
             **{
-                "test_bar.py": """
+                "test_setup_nonexisting_cwd.py": """
                 import os
                 import shutil
                 import tempfile
@@ -1320,7 +1327,7 @@ def test_cwd_changed(self, testdir):
                 os.chdir(d)
                 shutil.rmtree(d)
             """,
-                "test_foo.py": """
+                "test_test.py": """
                 def test():
                     pass
             """,