The latest pip version (20.1) doesn't work due to issue 3770

[yubrajbhoi]

Problem description

Pip version 20.0.2 works perfectly but the new version 20.1 uses semaphore from the multiprocessing package. Which isn't available in Android.

ImportError: This platform lacks a functioning sem_open implementation, therefore, the required synchronization primitives needed will not function, see issue 3770.

Steps to reproduce

Run pip list --outdated.

Expected behavior

It should work. Or we may be stuck with an outdated pip forever.

Additional information

Packages CPU architecture:
arm
Subscribed repositories:
# sources.list
deb https://termux.org/packages/ stable main
# science-repo (sources.list.d/science.list)
deb https://dl.bintray.com/grimler/science-packages-24 science stable
# game-repo (sources.list.d/game.list)
deb https://dl.bintray.com/grimler/game-packages-24 games stable
# unstable-repo (sources.list.d/unstable.list)
deb https://dl.bintray.com/xeffyr/unstable-packages unstable main
Updatable packages:
All packages up to date
Android version:
8.1.0
Kernel build information:
Linux localhost 3.18.71-perf-gea366bb-00016-g6e15bdb #1 SMP PREEMPT Mon Mar 4 18:13:35 CST 2019 armv7l Android
Device manufacturer:
motorola
Device model:
Moto G (5)

[yubrajbhoi]

Looks like someone already raised the issue at pypa/pip#8161. Hopefully it will get merged soon.

[deveshks]

Could you also provide the entire traceback which you see when you run pip list --outdated ?

[yubrajbhoi]

@deveshks Sure.

ERROR: Exception:
Traceback (most recent call last):
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/synchronize.py", line 28, in <module>
    from _multiprocessing import SemLock, sem_unlink
ImportError: cannot import name 'SemLock' from '_multiprocessing' (/data/data/com.termux/files/usr/lib/python3.8/lib-dynload/_multiprocessing.cpython-38.so)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/data/data/com.termux/files/home/code/python/venvs/test_pip/lib/python3.8/site-packages/pip/_internal/cli/base_command.py", line 188, in _main
    status = self.run(options, args)
  File "/data/data/com.termux/files/home/code/python/venvs/test_pip/lib/python3.8/site-packages/pip/_internal/commands/list.py", line 160, in run
    packages = self.get_outdated(packages, options)
  File "/data/data/com.termux/files/home/code/python/venvs/test_pip/lib/python3.8/site-packages/pip/_internal/commands/list.py", line 167, in get_outdated
    return [
  File "/data/data/com.termux/files/home/code/python/venvs/test_pip/lib/python3.8/site-packages/pip/_internal/commands/list.py", line 167, in <listcomp>
    return [
  File "/data/data/com.termux/files/home/code/python/venvs/test_pip/lib/python3.8/site-packages/pip/_internal/commands/list.py", line 216, in iter_packages_latest_infos
    pool = Pool(DEFAULT_POOLSIZE)
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/dummy/__init__.py", line 124, in Pool
    return ThreadPool(processes, initializer, initargs)
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/pool.py", line 922, in __init__
    Pool.__init__(self, processes, initializer, initargs)
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/pool.py", line 196, in __init__
    self._change_notifier = self._ctx.SimpleQueue()
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/context.py", line 113, in SimpleQueue
    return SimpleQueue(ctx=self.get_context())
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/queues.py", line 336, in __init__
    self._rlock = ctx.Lock()
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/context.py", line 67, in Lock
    from .synchronize import Lock
  File "/data/data/com.termux/files/usr/lib/python3.8/multiprocessing/synchronize.py", line 30, in <module>
    raise ImportError("This platform lacks a functioning sem_open" +
ImportError: This platform lacks a functioning sem_open implementation, therefore, the required synchronization primitives needed will not function, see issue 3770.