Issue2205

THREADS=8 jython start_threads

With various values for this environment variable you will see various behaviours.
With low enough values, this results in no error. (The script has no output upon successful completion.)

Sometimes:

[acharis@workstation ~]% THREADS=8 /tmp/jython2.7b3/jython start_threads
Exception in thread Thread-5:Traceback (most recent call last):
  File "/tmp/jython2.7b3/Lib/threading.py", line 207, in _Thread__bootstrap
    self.run()
  File "start_threads", line 11, in run
    os.system("cat /etc/hostname > /dev/null")
  File "/tmp/jython2.7b3/Lib/subprocess.py", line 500, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/tmp/jython2.7b3/Lib/subprocess.py", line 830, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/tmp/jython2.7b3/Lib/subprocess.py", line 1315, in _execute_child
    args = _shell_command + args
TypeError: unsupported operand type(s) for +: 'NoneType' and 'list'

Other times:

AttributeError: 'module' object has no attribute 'call'

Other times: 

NameError: global name 'Popen' is not defined

So this due to a race on the module import lock in org.python.core.imp; currently only importName acquires it, but the posix module uses (implicitly) import_first, via load.

The workaround until this is fixed is to import subprocess before any threading is performed.

Target beta 4

Must fix

Fixed as of https://hg.python.org/jython/rev/0ee9d9d530ba