multiprocessing pool + subprocess ValueError: empty range for randrange

[ghost]

BPO	36578
Files	demo.py

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2019-04-09.16:11:03.423>
created_at = <Date 2019-04-09.15:54:39.732>
labels = ['invalid', 'type-bug', 'library']
title = 'multiprocessing pool + subprocess ValueError: empty range for randrange'
updated_at = <Date 2019-04-09.16:11:03.418>
user = None

bugs.python.org fields:

activity = <Date 2019-04-09.16:11:03.418>
actor = 'SilentGhost'
assignee = 'none'
closed = True
closed_date = <Date 2019-04-09.16:11:03.423>
closer = 'SilentGhost'
components = ['Library (Lib)']
creation = <Date 2019-04-09.15:54:39.732>
creator = '\xe5\xad\x91\xe5\xbd\xb1'
dependencies = []
files = ['48256']
hgrepos = []
issue_num = 36578
keywords = []
message_count = 3.0
messages = ['339767', '339769', '339770']
nosy_count = 2.0
nosy_names = ['SilentGhost', '\xe5\xad\x91\xe5\xbd\xb1']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue36578'
versions = ['Python 3.6']

[ghost]

== 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.

[ghost]

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

[SilentGhost]

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.