Import Error with ESMPy 8.0.0 on Mac due to mixed conda channels

[JiaweiZhuang]

I got the classic ImportError: The ESMF shared library did not load properly and image not found with importing esmpy 8.0.0 on Mac. I've fixed the problem via JiaweiZhuang/xESMF#54 (comment) and conda-forge Tips & tricks. Basically, add this block to my $HOME/.condarc:

channel_priority: strict
channels:
  - conda-forge
  - defaults

This is probably not a bug. Just post the issue here for reference. I didn't run into this problem with esmpy<=7.1.0. Not sure why esmpy 8.0.0 needs such a fix.

The install command:

conda create -n esmpy python=3.6  # same problem for 3.7
conda activate esmpy
conda install -c conda-forge esmpy=8.0.0

The error without strictly forcing conda-forge channels.

>>> import ESMF
Traceback (most recent call last):
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/interface/loadESMF.py", line 125, in <module>
    _ESMF = np.ctypeslib.load_library('libesmf_fullylinked',libsdir)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/numpy/ctypeslib.py", line 152, in load_library
    return ctypes.cdll[libpath]
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 423, in __getitem__
    return getattr(self, name)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 418, in __getattr__
    dll = self._dlltype(name)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 348, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: dlopen(/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/libesmf_fullylinked.dylib, 6): Library not loaded: @rpath/libmpifort.12.dylib
  Referenced from: /Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/libesmf_fullylinked.dylib
  Reason: image not found
Traceback (most recent call last):
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/interface/loadESMF.py", line 125, in <module>
    _ESMF = np.ctypeslib.load_library('libesmf_fullylinked',libsdir)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/numpy/ctypeslib.py", line 152, in load_library
    return ctypes.cdll[libpath]
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 423, in __getitem__
    return getattr(self, name)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 418, in __getattr__
    dll = self._dlltype(name)
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/ctypes/__init__.py", line 348, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: dlopen(/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/libesmf_fullylinked.dylib, 6): Library not loaded: @rpath/libmpifort.12.dylib
  Referenced from: /Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/libesmf_fullylinked.dylib
  Reason: image not found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/__init__.py", line 70, in <module>
    from ESMF.api.esmpymanager import *
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/api/esmpymanager.py", line 11, in <module>
    from ESMF.interface.cbindings import *
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/interface/cbindings.py", line 13, in <module>
    from ESMF.interface.loadESMF import _ESMF
  File "/Users/zhuangjw/Research/Computing/miniconda/envs/esmpy/lib/python3.6/site-packages/ESMF/interface/loadESMF.py", line 131, in <module>
    raise ImportError('The ESMF shared library did not load properly.')
ImportError: The ESMF shared library did not load properly.

Conda info:

$conda info

     active environment : esmpy
    active env location : /Users/zhuangjw/Research/Computing/miniconda/envs/esmpy
            shell level : 1
       user config file : /Users/zhuangjw/.condarc
 populated config files :
          conda version : 4.7.12
    conda-build version : not installed
         python version : 3.7.4.final.0
       virtual packages :
       base environment : /Users/zhuangjw/Research/Computing/miniconda  (writable)
           channel URLs : https://repo.anaconda.com/pkgs/main/osx-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/osx-64
                          https://repo.anaconda.com/pkgs/r/noarch
          package cache : /Users/zhuangjw/Research/Computing/miniconda/pkgs
                          /Users/zhuangjw/.conda/pkgs
       envs directories : /Users/zhuangjw/Research/Computing/miniconda/envs
                          /Users/zhuangjw/.conda/envs
               platform : osx-64
             user-agent : conda/4.7.12 requests/2.22.0 CPython/3.7.4 Darwin/16.7.0 OSX/10.12.6
                UID:GID : 501:20
             netrc file : None
           offline mode : False