[Win] Move EWS Processing off of Cygwin

[Brent Fulgham]

Based on my observations over the past few weeks, it appears that the most frequent cause of Windows EWS failures are due to Cygwin rebasing issues.

These errors look like the following:

Failed to run "['/home/buildbot/WebKit/Tools/Scripts/webkit-patch', '--status-host=webkit-queues.appspot.com', '--bot-id=ews204', 'clean', '--port=win']" exit_code: 1 cwd: /home/buildbot/WebKit

      0 [main] python2.7 716 child_info_fork::abort: address space needed by 'cygffi-6.dll' (0x3F0000) is already occupied
Traceback (most recent call last):
  File "/home/buildbot/WebKit/Tools/Scripts/webkit-patch", line 84, in <module>
    main()
  File "/home/buildbot/WebKit/Tools/Scripts/webkit-patch", line 79, in main
    WebKitPatch(os.path.abspath(__file__)).main()
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/tool/multicommandtool.py", line 296, in main
    self.handle_global_options(options)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/tool/main.py", line 94, in handle_global_options
    self.initialize_scm(options.patch_directories)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/host.py", line 81, in initialize_scm
    self._checkout = Checkout(detector.default_scm(patch_directories))
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/detection.py", line 55, in default_scm
    scm_system = self.detect_scm_system(cwd, patch_directories)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/detection.py", line 72, in detect_scm_system
    return SVN(cwd=absolute_path, patch_directories=patch_directories, filesystem=self._filesystem, executive=self._executive)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/svn.py", line 81, in __init__
    SCM.__init__(self, cwd, **kwargs)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/scm.py", line 67, in __init__
    self.checkout_root = self.find_checkout_root(self.cwd)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/svn.py", line 125, in find_checkout_root
    if uuid != self.find_uuid(path):
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/svn.py", line 103, in find_uuid
    if not self.in_working_directory(path):
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/svn.py", line 99, in in_working_directory
    exit_code = executive.run_command(svn_info_args, cwd=path, return_exit_code=True)
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/system/executive.py", line 435, in run_command
    close_fds=self._should_close_fds())
  File "/home/buildbot/WebKit/Tools/Scripts/webkitpy/common/system/executive.py", line 506, in popen
    return subprocess.Popen(string_args, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1223, in _execute_child
    self.pid = os.fork()
OSError: [Errno 11] Resource temporarily unavailable

It seems like moving away from running Windows EWS on top of Cygwin would provide a significant boost in reliability.

[Brent Fulgham]

It might also be possible to somehow work the Cygwin 'rebaseall' script into our cycle.

[Radar WebKit Bug Importer]

<rdar://problem/19609012>

[Fujii Hironori]

AppleWin was removed. WinCairo EWS isn't using Cygwin.