multiprocessing.Manager() + cd leads to EOFError · Issue #890 · nedbat/coveragepy (original) (raw)

Describe the bug
Change of directory + multiprocessing.Manager() entrance results to EOFError with coverage 5.0

To Reproduce

1. What version of Python are you using?
   Python 3.8.0rc1
   It also fails on travis with Python 3.6.3
2. What version of coverage.py are you using? coverage debug sys

-- sys -------------------------------------------------------
                   version: 5.0
                  coverage: /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python3.8/site-packages/coverage/__init__.py
                    tracer: -none-
                   CTracer: available
      plugins.file_tracers: -none-
       plugins.configurers: -none-
 plugins.context_switchers: -none-
         configs_attempted: .coveragerc
              configs_read: .coveragerc
               config_file: .coveragerc
           config_contents: '[run]\nconcurrency = multiprocessing'
                 data_file: -none-
                    python: 3.8.0rc1 (default, Oct  1 2019, 21:48:24) [GCC 7.4.0]
                  platform: Linux-4.15.0-70-generic-x86_64-with-glibc2.27
            implementation: CPython
                executable: /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/bin/python
              def_encoding: utf-8
               fs_encoding: utf-8
                       pid: 11108
                       cwd: /mnt/md0/Documents/PycharmProjects/remote-runner
                      path: /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/bin
                            /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python38.zip
                            /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python3.8
                            /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python3.8/lib-dynload
                            /usr/lib/python3.8
                            /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python3.8/site-packages
                            /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/lib/python3.8/site-packages/remote_runner-0.2.0-py3.8.egg
               environment: -none-
              command_line: /mnt/md0/Documents/PycharmProjects/remote-runner/venv-3.8/bin/coverage debug sys
           sqlite3_version: 2.6.0
    sqlite3_sqlite_version: 3.22.0

1. --
2. What code are you running?

import multiprocessing import os

if not os.path.exists("./tmp"): os.mkdir("./tmp") os.chdir("./tmp")

with multiprocessing.Manager() as manager: pass

print("ok")

1. What commands did you run? python -m coverage run repro.py

Traceback (most recent call last):
  File "repro.py", line 7, in <module>
    with multiprocessing.Manager() as manager:
  File "/usr/lib/python3.8/multiprocessing/context.py", line 57, in Manager
    m.start()
  File "/usr/lib/python3.8/multiprocessing/managers.py", line 583, in start
    self._address = reader.recv()
  File "/usr/lib/python3.8/multiprocessing/connection.py", line 250, in recv
    buf = self._recv_bytes()
  File "/usr/lib/python3.8/multiprocessing/connection.py", line 414, in _recv_bytes
    buf = self._recv(4)
  File "/usr/lib/python3.8/multiprocessing/connection.py", line 383, in _recv
    raise EOFError
EOFError

python repro.py

Expected behavior
ok message

Additional context
Seems like bug was introduced with 5.0 release