Couldn't import convolution after python update to 3.7.4

After last conda revision:

2019-08-12 16:24:32  (rev 57)
     anaconda  {2019.07 -> custom}
     bokeh  {1.2.0 -> 1.3.4}
     ca-certificates  {2019.5.15 -> 2019.5.15}
     certifi  {2019.6.16 -> 2019.6.16}
     chardet  {3.0.4 -> 3.0.4}
     dask  {2.1.0 -> 2.2.0}
     dask-core  {2.1.0 -> 2.2.0}
     distributed  {2.1.0 -> 2.2.0}
     docutils  {0.14 -> 0.15.1}
     importlib_metadata  {0.17 -> 0.19}
     ipython  {7.6.1 -> 7.7.0}
     ipywidgets  {7.5.0 -> 7.5.1}
     json5  {0.8.4 -> 0.8.5}
     jupyterlab_server  {1.0.0 -> 1.0.0}
     more-itertools  {7.0.0 -> 7.2.0}
     pandas  {0.24.2 -> 0.25.0}
     pytest-remotedata  {0.3.1 -> 0.3.2}
     python  {3.7.3 -> 3.7.4}
     python-libarchive-c  {2.8 -> 2.8}
     qtconsole  {4.5.1 -> 4.5.2}
     soupsieve  {1.8 -> 1.9.2}
     statsmodels  {0.10.0 -> 0.10.1}
     wurlitzer  {1.0.2 -> 1.0.3}
     zipp  {0.5.1 -> 0.5.2}
    +_anaconda_depends-2019.03
    +fsspec-0.4.0
    +tbb-2019.4

Couldn’t import convolution anymore:

from astropy.convolution import *                                                                                                                                                         
7.4.0
---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
/opt/anaconda/lib/python3.7/site-packages/astropy/convolution/convolve.py in <module>
     26 try:
---> 27     _convolve = load_library("_convolve", LIBRARY_PATH)
     28 except Exception:

/opt/anaconda/lib/python3.7/site-packages/numpy/ctypeslib.py in load_library(libname, loader_path)
    156         ## if no successful return in the libname_ext loop:
--> 157         raise OSError("no file with expected extension")
    158 

OSError: no file with expected extension

During handling of the above exception, another exception occurred:

ImportError                               Traceback (most recent call last)
<ipython-input-1-36349150199c> in <module>
----> 1 from astropy.convolution import *

/opt/anaconda/lib/python3.7/site-packages/astropy/convolution/__init__.py in <module>
      6 from .utils import discretize_model  # noqa
      7 
----> 8 from .convolve import convolve, convolve_fft, interpolate_replace_nans, convolve_models  # noqa

/opt/anaconda/lib/python3.7/site-packages/astropy/convolution/convolve.py in <module>
     27     _convolve = load_library("_convolve", LIBRARY_PATH)
     28 except Exception:
---> 29     raise ImportError("Convolution C extension is missing. Try re-building astropy.")
     30 
     31 # The GIL is automatically released by default when calling functions imported

ImportError: Convolution C extension is missing. Try re-building astropy.

Probably related to https://github.com/astropy/astropy/issues/8032

[bsipocz]

A fix for this is expected to be out later today (once that’s done, we’ll remove the version pinning in ci-helpers, too): https://github.com/ContinuumIO/anaconda-issues/issues/11195

[jamienoss]

@mroldrobot My apologies, in https://github.com/astropy/astropy/issues/9122#issuecomment-520937808 I wrote python=3.6.3 when I meant python=3.7.3 (now edited).

I just did as you did on both conda 4.7.10 and 4.7.11 and get the same behavior as I did before in that it works, I can import astropy.convolution. I get the same as you when going from python=3.6.3 -> 3.7.4, in that astropy is downgraded (no idea why), however, no such downgrade occurs for the version bump as noted in your opening comment: 3.7.3 -> 3.7.4.

With conda 4.7.11 and conda create -n astropy-9122 python=3.6.3 astropy;conda activate astropy-9122;conda install python=3.7.4

Collecting package metadata (current_repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: /Users/jnoss/anaconda3/envs/9122

  added / updated specs:
    - python=3.7.4


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    astropy-2.0.9              |   py37h1d22016_1         5.3 MB
    pytest-3.2.2               |             py_0         129 KB  conda-forge
    ------------------------------------------------------------
                                           Total:         5.4 MB

The following packages will be REMOVED:

  atomicwrites-1.3.0-py36_1
  attrs-19.1.0-py36_1
  more-itertools-7.2.0-py36_0
  packaging-19.0-py36_0
  psutil-5.6.3-py36h1de35cc_0
  pytest-arraydiff-0.3-py36h39e3cac_0
  pytest-astropy-0.5.0-py36_0
  pytest-doctestplus-0.3.0-py36_0
  pytest-openfiles-0.3.2-py36_0
  pytest-remotedata-0.3.2-py36_0
  six-1.12.0-py36_0
  wcwidth-0.1.7-py36h8c6ec74_0

The following packages will be UPDATED:

  openssl                                 1.0.2s-h1de35cc_0 --> 1.1.1c-h1de35cc_1
  python                                   3.6.3-h47c878a_7 --> 3.7.4-h359304d_0

The following packages will be SUPERSEDED by a higher-priority channel:

  pytest              pkgs/main/osx-64::pytest-5.0.1-py36_0 --> conda-forge/noarch::pytest-3.2.2-py_0

The following packages will be DOWNGRADED:

  astropy                              3.2.1-py36h1de35cc_0 --> 2.0.9-py37h1d22016_1
  certifi                                  2019.6.16-py36_1 --> 2019.6.16-py37_1
  importlib_metadata                            0.19-py36_0 --> 0.19-py37_0
  mkl_fft                             1.0.12-py36h5e564d8_0 --> 1.0.12-py37h5e564d8_0
  mkl_random                           1.0.2-py36h27c97d8_0 --> 1.0.2-py37h27c97d8_0
  numpy                               1.16.4-py36hacdab7b_0 --> 1.16.4-py37hacdab7b_0
  numpy-base                          1.16.4-py36h6575580_0 --> 1.16.4-py37h6575580_0
  pip                                         19.1.1-py36_0 --> 19.1.1-py37_0
  py                                           1.8.0-py36_0 --> 1.8.0-py37_0
  setuptools                                  41.0.1-py36_0 --> 41.0.1-py37_0
  wheel                                       0.33.4-py36_0 --> 0.33.4-py37_0

However, with conda 4.7.10 and 4.7.11 I get no downgrade of astropy for the python update from 3.7.3 -> 3.7.4, and I can successfully import astropy.convolution.

conda install python=3.7.4
Collecting package metadata (current_repodata.json): done
Solving environment: done


==> WARNING: A newer version of conda exists. <==
  current version: 4.7.10
  latest version: 4.7.11

Please update conda by running

    $ conda update -n base -c defaults conda



## Package Plan ##

  environment location: /Users/jnoss/anaconda3/envs/astropy-9122

  added / updated specs:
    - python=3.7.4


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    python-3.7.4               |       h359304d_0        21.6 MB
    ------------------------------------------------------------
                                           Total:        21.6 MB

The following packages will be UPDATED:

  python                                   3.7.3-h359304d_0 --> 3.7.4-h359304d_0