PyDev 3.9.2 - Cannot attach the debugger to gevent-based processes

Question

I'm having problems with attaching to gevent-based processes with the PyDev's debugger under PyDev 3.9.2.

It works fine in PyDev 3.9.1 and LiClipse 3.9.1, just not with 3.9.2 which is the latest PyDev right now (6 Feb, 2015).

It also works properly when a piece of code is run directly from PyDev's debugger rather than externally.

Note that it doesn't depend on whether there are breakpoints set (enabled or not) - the mere fact of attaching to a process suffices for the exception to be raised.

Here is a sample module to reproduce the behaviour along with two exceptions - one from PyDev and the other one from the gevent code's point of view.

Can anyone please shed any light on it? Thanks a lot.

from gevent.monkey import patch_all
patch_all()

import threading
import gevent

def myfunc():
    t = threading.current_thread()
    print(t.name)

while True:
    gevent.spawn(myfunc)
    gevent.sleep(1)

Debug Server at port: 5678
Traceback (most recent call last):
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd_attach_to_process/attach_script.py", line 16, in attach
    patch_multiprocessing=False,
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 1828, in settrace
    patch_multiprocessing,
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 1920, in _locked_settrace
    CheckOutputThread(debugger).start()
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 261, in start
    thread.start()
  File "/usr/lib/python2.7/threading.py", line 750, in start
    self.__started.wait()
  File "/usr/lib/python2.7/threading.py", line 620, in wait
    self.__cond.wait(timeout)
  File "/usr/lib/python2.7/threading.py", line 339, in wait
    waiter.acquire()
  File "_semaphore.pyx",...

Traceback (most recent call last):
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd_attach_to_process/attach_script.py", line 16, in attach
    patch_multiprocessing=False,
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 1828, in settrace
    patch_multiprocessing,
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 1920, in _locked_settrace
    CheckOutputThread(debugger).start()
  File "/opt/slow/01/data/install/pydev/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc/pydevd.py", line 261, in start
    thread.start()
  File "/usr/lib/python2.7/threading.py", line 750, in start
    self.__started.wait()
  File "/usr/lib/python2.7/threading.py", line 620, in wait
    self.__cond.wait(timeout)
  File "/usr/lib/python2.7/threading.py", line 339, in wait
    waiter.acquire()
  File "_semaphore.pyx", line 112, in gevent._semaphore.Semaphore.acquire (gevent/gevent._semaphore.c:3004)
  File "/home/dsuch/projects/pydev-plugin/pydev-plugin/local/lib/python2.7/site-packages/gevent/hub.py", line 330, in switch
    switch_out()
  File "/home/dsuch/projects/pydev-plugin/pydev-plugin/local/lib/python2.7/site-packages/gevent/hub.py", line 334, in switch_out
    raise AssertionError('Impossible to call blocking function in the event loop callback')
AssertionError: Impossible to call blocking function in the event loop callback