== output ==
python2 /tmp/demo.py 
31749 task#1 result:(False, 'ls: cannot access alksdfjalkdsfadsfk: No such file or directoryn') 
31751 task#2 result:(False, 'ls: cannot access alksdfjalkdsfadsfk: No such file or directoryn') 
31752 task#3 result:(False, '3n') 
31750 task#4 result:(False, '4n') 
31749 task#6 result:(False, '6n') 
31752 task#7 result:(False, '7n') 
31750 task#8 result:(False, '8n') 
31751 task#9 result:(False, '9n') 
Traceback (most recent call last):
  File "/tmp/demo.py", line 74, in <module>
    runner()
  File "/tmp/demo.py", line 64, in runner
    rc_orig = value.get()
  File "/usr/lib64/python2.7/multiprocessing/pool.py", line 554, in get
    raise self._value
ValueError: empty range for randrange() (1,1, 0)

== The python2.7 demo ==
http://paste.ubuntu.org.cn/4379593

== More ==
The interesting thing is if you modify demo.py like this .

http://paste.ubuntu.org.cn/4379595

Almost the code can be run normal.

My python version info:

Python 2.7.13 (default, Sep 26 2018, 18:42:22) 
[GCC 6.3.0 20170516] on linux2

Python 3.5.3 (default, Sep 27 2018, 17:25:39) 
[GCC 6.3.0 20170516] on linux

The error you're seeing stems from this bit of code:

random.randint(1, 0)

With zero resulting from `taskid % 5` operation for values of taskid divisible by 5. Obviously, when you comment out this line you're not seeing the error.

type: behavior

nosy: + SilentGhost
messages: + msg339770
resolution: not a bug
stage: resolved