status: fails whenever an experiment is running

[mattseddon]

Bug Report

Description

In the vs code extension we use file watchers to trigger commands that provide data for the UI. status, list and diff are run on any change in the workspace. If our demo project status will fail for the entire duration that an experiment is running.

Note: We have implemented a retry on our end (that uses an exponential backoff) to cater for this situation.

Reproduce

1. run dvc exp run
2. wait for the experiment to start
3. run dvc status
4. the command should fail

Expected

In this instance it would be good for the command to wait for the repository to be unlocked before returning. I know that there are instances of extremely long running experiments but is there a gap where status would be able to return a reliable result?

Environment information

Output of dvc doctor:

$ dvc doctor

Additional Information (if any):

Closely related to #6132. Seems like a more complicated issue to solve. Happy to discuss further if required.

Thanks!

[mattseddon]

Will not be required after data:status is implemented.