How can I update multiple configuration fields of a composer environment at once?

When I try to run gcloud composer environments update and specify --update-labels and --update-env-variables I get an error:

Composer deployment failed with error: ERROR: (gcloud.composer.environments.update) Exactly one 
of (.....) must be specified.

That is a very frustrating limitation for automation purposes.

Is this a limitation of the cli or the API proper? I want my deployment scripts to make it possible to update multiple values and I really don't want to have to loop over all options and make a call for each one- even if I can use --async.

I wasn't able to find answers in the docs. Can I get around this by calling the API programmatically with the SDK?

Would this command be applicable to your use case? I tried just repeating the command with update env variable and update labels:

user@cloudshell:~ (my-project)$ gcloud composer environments update \
    samplenestor \
    --location us-central1 \
    --update-env-variables=SAMPLEKEY=700
gcloud composer environments update \
    samplenestor \
    --location us-central1 \
    --update-labels samplelabel=guitar

Result:

UPDATE:

It appears that this is a limitation for Cloud Composer at the moment hence the error mentioned in the question:

> Only one update type may be included in a single request's updateMask. For example, one cannot update both the PyPI packages and labels in the same request.

For the mean time I have created a feature request/issue tracker for this inquiry that can be followed for updates:
https://issuetracker.google.com/issues/296867228