get: make it work for experiments and/or improve message #7169

dvc get --rev exp-name
dvc get --rev exp-ref

should work and I should be able to get artifacts, datasets w/o doing heavy apply.

Now the message:

$ dvc get example-get-started/ model.pkl --rev 73c7c57
ERROR: failed to get 'model.pkl' from 'example-get-started/' - '404 Not Found'

is confusing. So, even if for some reason we decide it's not needed we have to improve the message and also solve #5355

Use cases:

• I want to get a few models to compare them side by side now in the workspace
• I want to get a model/checkpoint w/o affecting my workspace
• I want to get a dataset w/o doing full apply

To me it felt very natural to expect, and I though this is a bug.

More context from Slack:

@pmrowla

exp names are already supposed to be accepted anywhere in DVC that supports --rev, the issue with dvc get is probably that we do not pull exp refs when we make the erepo clone. I don’t think we have a ticket for this right now

So, this can be considered a bug?