Unable to use Spyder with conda --stack

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1

I’m trying to run Spyder in Anaconda under a "–stack"ed environment. I’ve had no luck getting the Spyder kernel to be aware of modules in the stacked environment.

To be clear, I’m not looking to go down any rabbit holes of setting up explicit Spyder kernels or module paths. I would just like to find the simplest, most Anaconda-native way to achieve this – as if the stacked environment was a single environment.

Background:
base environment has Spyder installed
aras environment has modules including ‘oauthlib’
The script runs on the command line under aras with or without the stacking.

To reproduce:
Open terminal (starts in base environment)
Run conda activate aras
Run spyder to launch Spyder.
On Spyder, try run the offending script.
Observe error: ModuleNotFoundError: No module named 'oauthlib'

Things I’ve tried:
I can change the stack order of the two environments, and that still doesn’t make Spyder aware of the modules.
I have auto_stack config set to 1; I also explicitly try with conda --stack with no difference.
I have not found this specific issue covered in Google searches or in this community. It does seem like --stack is a new feature.

Is this a bug/oversight in Anaconda or Spyder? Am I completely missing the point of --stack? Is there an easy/native fix short of messing with Spyder kernel/module paths?

2

For those who want to know, here’s the conda info:

     active environment : aras
    active env location : /opt/anaconda3/envs/aras
            shell level : 2
       user config file : /Users/berka/.condarc
 populated config files : /opt/anaconda3/.condarc
                          /Users/berka/.condarc
          conda version : 24.11.2
    conda-build version : 24.11.2
         python version : 3.12.7.final.0
                 solver : libmamba (default)
       virtual packages : __archspec=1=m1
                          __conda=24.11.2=0
                          __osx=15.2=0
                          __unix=0=0
       base environment : /opt/anaconda3  (writable)
      conda av data dir : /opt/anaconda3/etc/conda
  conda av metadata url : None
           channel URLs : https://repo.anaconda.com/pkgs/main/osx-arm64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/osx-arm64
                          https://repo.anaconda.com/pkgs/r/noarch
          package cache : /opt/anaconda3/pkgs
                          /Users/berka/.conda/pkgs
       envs directories : /opt/anaconda3/envs
                          /Users/berka/.conda/envs
               platform : osx-arm64
             user-agent : conda/24.11.2 requests/2.32.3 CPython/3.12.7 Darwin/24.2.0 OSX/15.2 solver/libmamba conda-libmamba-solver/24.11.1 libmambapy/2.0.5 aau/0.5.0 c/. s/. e/.
                UID:GID : 501:20
             netrc file : None
           offline mode : False