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= Using a chroot as working environment =

Although WebKit working environment and building system is quite self contained, some people like still to work in a `chroot` so they can move the complete environment from a computer to another or from a distribution to a different one without major problems and keeping their own production environment clean and totally independent from WebKit development.

Working in a `chroot`, however, brings some drawbacks. Here you can find some tips, common problems and solutions.

== Running tests into the chroot ==

WebKitGtkLayoutTests explains how to run WebKit tests.

=== Running python based test with multiprocess support ===

I'm running my development environment in a schroot with Ubuntu in an
Ubuntu host.

It hapenned to me the following error when trying to run the tests

{{{
$ ./Tools/Scripts/run-webkit-tests --gtk --debug
Using port 'gtk'
Test configuration: <, x86, debug>
Placing test results in /opt/webkit/WebKit.git/WebKitBuild/Debug/layout-test-results
Baseline search path: gtk -> generic
Using Debug build
Pixel tests disabled
Regular timeout: 12000, slow test timeout: 60000
Command line: /opt/webkit/WebKit.git/WebKitBuild/Debug/Programs/DumpRenderTree -

Found 31495 tests; running 28693, skipping 2802.
Running 4 DumpRenderTrees in parallel over 727 shards (1 locked).

Releasing server lock ...
OSError raised: [Errno 38] Function not implemented
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/layout_tests/run_webkit_tests.py", line 110, in run
      unexpected_result_count = manager.run(args)
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py", line 411, in run
      self._run_tests(self._test_names, result_summary, int(self._options.child_processes))
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py", line 464, in _run_tests
      return self._runner.run_tests(test_inputs, self._expectations, result_summary, num_workers, needs_http, needs_websockets, self._retrying)
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/layout_tests/controllers/layout_test_runner.py", line 141, in run_tests
      with message_pool.get(self, self._worker_factory, num_workers, self._port.worker_startup_delay_secs(), self._port.host) as pool:
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/common/message_pool.py", line 61, in get
      return _MessagePool(caller, worker_factory, num_workers, worker_startup_delay_secs, host)
    File "/opt/webkit/WebKit.git/Tools/Scripts/webkitpy/common/message_pool.py", line 79, in __init__
      self._messages_to_worker = multiprocessing.Queue()
    File "/usr/lib/python2.7/multiprocessing/__init__.py", line 218, in Queue
      return Queue(maxsize)
    File "/usr/lib/python2.7/multiprocessing/queues.py", line 63, in __init__
      self._rlock = Lock()
    File "/usr/lib/python2.7/multiprocessing/synchronize.py", line 147, in __init__
      SemLock.__init__(self, SEMAPHORE, 1, 1)
    File "/usr/lib/python2.7/multiprocessing/synchronize.py", line 75, in __init__
      sl = self._semlock = _multiprocessing.SemLock(kind, value, maxvalue)
Failed to execute Tools/Scripts/new-run-webkit-tests at ./Tools/Scripts/run-webkit-tests line 126.
}}}

The reason is explained in this post
http://www.boris.co/2012/02/server-ubuntu-11.html

Python's multithreading requires /dev/shm to work. In Ubuntu /dev/shm
points to /run/shm by default. Rename (or delete, I doubt it is
necessary anymore) existing /dev/shm.

Create /dev/shm directory

{{{
$ sudo -i (become root)
$ mkdir /dev/shm
}}}

Add to /etc/fstab mounting of /dev/shm command

{{{
tmpfs /dev/shm    tmpfs   defaults,noexec,nosuid     0     0
}}}

Mount all unmounted filesystems from /etc/fstab.

{{{
$ mount -a
}}}

You may need to do this into your schroot too.


== Pulse Audio ==