ImportError in Python 3.6 importlib

@bsipocz

I see this in Python 3.6 test suites. Is this safe to ignore or should be fixed somehow? Should we move this to astropy-helpers? I am not sure where this is coming from.

home/travis/miniconda/envs/test/lib/python3.6/importlib/_bootstrap.py:205:
ImportWarning: can't resolve package from __spec__ or __package__,
falling back on __name__ and __path__

  return f(*args, **kwds)

p.s. Instead of decreasing the number of issues, I am increasing it. Sorry, @bsipocz !

@pllim

@pllim - do you still see this? (I'm not sure what the problem was here, but maybe the helpers update had a good side effect...)

I'll check when I get the chance and let you know. 😄

I also see these warnings, so did a quick debugging:

❯ PYTHONWARNINGS='error::ImportWarning' python setup.py test
running test
running build
running build_py
running pre_hook from astropy._erfa.setup_package for build_py command
running pre_hook from astropy.modeling.setup_package for build_py command
running build_ext
running pre_hook from astropy._erfa.setup_package for build_ext command
running pre_hook from astropy.modeling.setup_package for build_ext command
Traceback (most recent call last):
  File "setup.py", line 105, in <module>
    **package_info
  File "/home/simon/miniconda3/lib/python3.6/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/home/simon/miniconda3/lib/python3.6/distutils/dist.py", line 955, in run_commands
    self.run_command(cmd)
  File "/home/simon/miniconda3/lib/python3.6/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/home/simon/dev/astropy/astropy/tests/command.py", line 201, in run
    self._build_temp_install()
  File "/home/simon/dev/astropy/astropy/tests/command.py", line 241, in _build_temp_install
    self.run_command('build')
  File "/home/simon/miniconda3/lib/python3.6/distutils/cmd.py", line 313, in run_command
    self.distribution.run_command(command)
  File "/home/simon/miniconda3/lib/python3.6/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/home/simon/miniconda3/lib/python3.6/distutils/command/build.py", line 135, in run
    self.run_command(cmd_name)
  File "/home/simon/miniconda3/lib/python3.6/distutils/cmd.py", line 313, in run_command
    self.distribution.run_command(command)
  File "/home/simon/miniconda3/lib/python3.6/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/home/simon/dev/astropy/astropy_helpers/astropy_helpers/setup_helpers.py", line 252, in run
    orig_run(self)
  File "/home/simon/dev/astropy/astropy_helpers/astropy_helpers/commands/build_ext.py", line 301, in run
    super(build_ext, self).run()
  File "/home/simon/miniconda3/lib/python3.6/site-packages/Cython/Distutils/old_build_ext.py", line 185, in run
    _build_ext.build_ext.run(self)
  File "/home/simon/miniconda3/lib/python3.6/distutils/command/build_ext.py", line 339, in run
    self.build_extensions()
  File "/home/simon/miniconda3/lib/python3.6/site-packages/Cython/Distutils/old_build_ext.py", line 192, in build_extensions
    ext.sources = self.cython_sources(ext.sources, ext)
  File "/home/simon/miniconda3/lib/python3.6/site-packages/Cython/Distutils/old_build_ext.py", line 203, in cython_sources
    from Cython.Compiler.Main \
  File "/home/simon/miniconda3/lib/python3.6/site-packages/Cython/Compiler/Main.py", line 28, in <module>
    from .Scanning import PyrexScanner, FileSourceDescriptor
  File "Cython/Compiler/Scanning.py", line 1, in init Cython.Compiler.Scanning (/home/ilan/minonda/conda-bld/cython_1482480352936/work/Cython-0.25.2/Cython/Compiler/Scanning.c:15387)
  File "/home/simon/miniconda3/lib/python3.6/site-packages/Cython/Plex/__init__.py", line 39, in <module>
    from .Scanners import Scanner
  File "Cython/Plex/Scanners.py", line 16, in init Cython.Plex.Scanners (/home/ilan/minonda/conda-bld/cython_1482480352936/work/Cython-0.25.2/Cython/Plex/Scanners.c:7116)
ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__

It is a Cython issue (cython/cython#1753 , cython/cython#1720) related to a new warning in Python 3.6 (http://bugs.python.org/issue25791).
cython/cython#1720 gives some workaround, i will try.

Hmm, adding the from __future__ import absolute_import does not work, the warning is triggered by Cython itself.

@saimn

Wow, good investigative work, @saimn !

So, since this is caused by bug upstream, should we close this issue here?

Hmm, some of these may come from Cython, but the ones in #6303 are definitely not as I don't have Cython installed there while I was testing the RC.

Maybe we can do something about these? Like a specific version of Cython that doesn't have this issue when I do the release? (still no Cython installed here though, this is with pip installed 2.0rc1).

bsipocz@tegla2:~$ PYTHONWARNINGS='error::ImportWarning' python3.6 -c 'import astropy;astropy.test()'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/sw/lib/python3.6/site-packages/astropy/utils/decorators.py", line 874, in test
    func = make_function_with_signature(func, name=name, **wrapped_args)
  File "/sw/lib/python3.6/site-packages/astropy/tests/runner.py", line 225, in test
    return runner.run_tests(**kwargs)
  File "/sw/lib/python3.6/site-packages/astropy/tests/runner.py", line 517, in run_tests
    from ..table import Table  # pylint: disable=W0611
  File "/sw/lib/python3.6/site-packages/astropy/table/__init__.py", line 44, in <module>
    from .column import Column, MaskedColumn, StringTruncateWarning, ColumnInfo
  File "/sw/lib/python3.6/site-packages/astropy/table/column.py", line 28, in <module>
    from .np_utils import fix_column_name
  File "/sw/lib/python3.6/site-packages/astropy/table/np_utils.py", line 19, in <module>
    from . import _np_utils
  File "astropy/table/_np_utils.pyx", line 8, in init astropy.table._np_utils (astropy/table/_np_utils.c:5760)
ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__

I think it happens inside the C code generated by Cython (see astropy/table/_np_utils.c:5760 above), so even if you don't have Cython installed.

@pllim

re @pllim :

So, since this is caused by bug upstream, should we close this issue here?

The workarounds didn't work for me, and it seems not so easy to fix on Cython's side, so maybe the warning could be filtered ?

I think this is still an issue until it is fixed upstream, so keeping this open for now.

There was a fix in Cython 0.27 but disabled since ("Reopening since the implementation in 0.27.0 is not complete and was disabled in 0.27.1" : cython/cython#1715).

This is only to bump this issue: i have just started a fresh install in the course of upgrading from 2.7 to 3.6, and am encountering this error. It seems only to throw a warning; i have not noticed any other adverse effects.

Yes, you can certainly ignore this warning. Ultimately this will go away seamlessly once addressed upstream (and we just keep it open in the meantime to avoid duplicate reports opened for it).

This is OBE since astropy no longer supports Python 3.6, and I can't reproduce it. There is a similar/maybe related issue at pypa/setuptools#1111 which I can see if I set -Werror::ImportWarning but the issue is already worked around upstream, and is only a problem when I explicitly convert the warning to an error.

We no longer see it because we are ignoring it in pytest.

astropy/setup.cfg

Line 134 in a97b833

ignore:can't resolve package from __spec__

Does this mean we can remove this from ignore list?

IMO we should remove it from the ignore list, or not close but update the description here if the warning is still raised in newer versions

Testing in #11928 🤞

It seems this was fixed in Cython 0.29 : https://github.com/cython/cython/blob/master/CHANGES.rst#029-2018-10-14

@saimn

@saimn - Cython hasn't been pinned to a minimum version in our tox, would you think we should just do that, even though it's not necessarily a requirement in setup.cfg?

@pllim

@pllim - It is pinned in pyproject.toml.

OK, fair enough, so we won't fail for building astropy, but could run into the issue when using a binary of other packages that might have been built with older versions?

Sorry I thought it was pllim above 😁
Yes I guess this could happen, but the cython releases is old enough now that we should be safe.

Navigation Menu

Repository navigation

ImportError in Python 3.6 importlib #6025

5 remaining items

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

ImportError in Python 3.6 importlib #6025

Description

Activity

bsipocz commented on Jun 26, 2017

pllim commented on Jun 27, 2017

saimn commented on Jun 27, 2017

saimn commented on Jun 27, 2017

pllim commented on Jun 28, 2017

pllim commented on Jun 28, 2017

bsipocz commented on Jun 29, 2017

bsipocz commented on Jun 29, 2017

saimn commented on Jun 29, 2017

saimn commented on Jun 29, 2017

5 remaining items

pllim commented on Nov 30, 2017

saimn commented on Nov 30, 2017

entaylor commented on Jan 5, 2018

bsipocz commented on Jan 5, 2018

embray commented on Jul 8, 2021

pllim commented on Jul 8, 2021

bsipocz commented on Jul 8, 2021

pllim commented on Jul 8, 2021

saimn commented on Jul 8, 2021

bsipocz commented on Jul 8, 2021

saimn commented on Jul 8, 2021

bsipocz commented on Jul 8, 2021

saimn commented on Jul 8, 2021

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions