webkitpy: Override TEMPDIR for Xvfb.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/linux.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
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 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
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@@ skipping 139 matching lines @@
         assert dummy_home != self._original_home
         self._filesystem.rmtree(dummy_home)
         self.host.environ['HOME'] = self._original_home
 
     def _start_xvfb(self):
         display = self._find_display()
         if not display:
             _log.warn('Failed to find a free display to start Xvfb.')
             return
 
+        # Parts of Xvfb use a hard-coded "/tmp" for its temporary directory.
+        # This can cause a failure when those parts expect to hardlink against
+        # files that were created in "TEMPDIR" / "TMPDIR".
+        #
+        # Since altering this behavior requires an Xvfb patch or some deep
+        # surgery, we instead opt to use the system "TEMPDIR" for this specific
+        # process.

[mithro, 2017/05/03 01:58:34]

Don't need this second paragraph.

[dnj, 2017/05/03 03:36:36]

Done.

+        #
+        # See: crbug.com/715848

[mithro, 2017/05/03 01:58:34]

https://crbug.com/XXXXX

[dnj, 2017/05/03 03:36:36]

Done.

+        env = self.host.environ.copy()
+        env['TEMPDIR'] = env['TMPDIR'] = '/tmp'

[mithro, 2017/05/03 01:58:34]

Can you log a warning if 'TEMPDIR' is set in the environment and not equal to
'/tmp'

[iannucci, 2017/05/03 02:06:36]

Actually... Why set TEMPDIR? That's only used on windows.

[dnj, 2017/05/03 03:36:36]

I can - however, this will generally not be set on developer systems, and will
always be set to not "/tmp" on bots. I'll log a warning if it's set and not
"/tmp".

[dnj, 2017/05/03 03:36:36]

I was overriding everything I saw in the log vars, but good to know - I'll just
set TMPDIR.

+
         _log.info('Starting Xvfb with display "%s".', display)
         self._xvfb_stdout = tempfile.NamedTemporaryFile(delete=False)
         self._xvfb_stderr = tempfile.NamedTemporaryFile(delete=False)
         self._xvfb_process = self.host.executive.popen(
             ['Xvfb', display, '-screen', '0', '1280x800x24', '-ac', '-dpi', '96'],
-            stdout=self._xvfb_stdout, stderr=self._xvfb_stderr)
+            stdout=self._xvfb_stdout, stderr=self._xvfb_stderr, env=env)
 
         # By setting DISPLAY here, the individual worker processes will
         # get the right DISPLAY. Note, if this environment could be passed
         # when creating workers, then we wouldn't need to modify DISPLAY here.
         self._original_display = self.host.environ.get('DISPLAY')
         self.host.environ['DISPLAY'] = display
 
         # The poll() method will return None if the process has not terminated:
         # https://docs.python.org/2/library/subprocess.html#subprocess.Popen.poll
         if self._xvfb_process.poll() is not None:
@@ skipping 42 matching lines @@
             self.host.filesystem.remove(self._xvfb_stdout.name)
         if self._xvfb_stderr and self.host.filesystem.exists(self._xvfb_stderr.name):
             for line in self.host.filesystem.read_text_file(self._xvfb_stderr.name).splitlines():
                 _log.warn('Xvfb stderr:  %s', line)
             self.host.filesystem.remove(self._xvfb_stderr.name)
         self._xvfb_stdout = self._xvfb_stderr = self._xvfb_process = None
 
     def _path_to_driver(self, target=None):
         binary_name = self.driver_name()
         return self._build_path_with_target(target, binary_name)