failed to push to demo.dataverse.org

[pdurbin]

I'm probably doing something wrong but here's the error I'm getting:

(venv) HMDC-beamish:alt pdurbin$ 
(venv) HMDC-beamish:alt pdurbin$ datalad add-sibling-dataverse https://demo.dataverse.org doi:10.70122/FK2/BUOCCS
A dataverse API token is required for access. Find it at https://demo.dataverse.org by clicking on your name at the top right corner and then clicking on API Token
token: 
A dataverse API token is required for access. Find it at https://demo.dataverse.org by clicking on your name at the top right corner and then clicking on API Token
token (repeat): 
Enter a name to save the credential securely for future reuse, or 'skip' to not save the credential
name: pdurbintoken

add_sibling_dataverse.storage(ok): . [dataverse-storage: https://demo.dataverse.org (DOI: doi:10.70122/FK2/BUOCCS)]
[INFO   ] Configure additional publication dependency on "dataverse-storage" 
add_sibling_dataverse(ok): . [dataverse: datalad-annex::?type=external&externaltype=dataverse&encryption=none&exporttree=no&url=https%3A//demo.dataverse.org&doi=doi:10.70122/FK2/BUOCCS (DOI: doi:10.70122/FK2/BUOCCS)]
(venv) HMDC-beamish:alt pdurbin$ 
(venv) HMDC-beamish:alt pdurbin$ datalad push --to dataverse
copy(ok): README.md (file) [to dataverse-storage...]                                                       
Update availability for 'dataverse':  75%|██████████████████▊      | 3.00/4.00 [00:00<00:00, 18.3k Steps/s]CommandError: 'git -c diff.ignoreSubmodules=none -c core.quotepath=false fetch dataverse git-annex' failed with exitcode 128
[DATALAD-ANNEX] fatal: couldn't find remote refs (repository deposit does not exist, or is inaccessible
(venv) HMDC-beamish:alt pdurbin$ 

I'm following https://docs.datalad.org/projects/dataverse/en/latest/tutorial.html

A single file was pushed to Dataverse but we expect more:

https://demo.dataverse.org/dataset.xhtml?persistentId=doi:10.70122/FK2/BUOCCS

I'm talking to @bpoldrack at the Distribits hackathon. We also looked at datalad -l debug push --to dataverse but the output above is sufficient.

We tried git config --global --add datalad.extensions.load next and that helped! All three files:

$ git remote -v
dataverse	datalad-annex::?type=external&externaltype=dataverse&encryption=none&exporttree=no&url=https%3A//demo.dataverse.org&doi=doi:10.70122/FK2/BUOCCS (fetch)
dataverse	datalad-annex::?type=external&externaltype=dataverse&encryption=none&exporttree=no&url=https%3A//demo.dataverse.org&doi=doi:10.70122/FK2/BUOCCS (push)
dataverse-storage

[bpoldrack]

Caveat: The trouble is that loading the next and dataverse extensions for patching datalad push and datalad clone respectively isn't properly pointed out in the docs.
With that, it turned out fine.