Discussion: unwrap tracker

[pcuenca]

Just opening this PR for discussion, related to the changes in 38fd30e

Observations:

• According to https://github.com/huggingface/accelerate/blob/38fd30e764ea87ef86e7d69fcba559c3605925b1/docs/source/usage_guides/tracking.mdx#accessing-the-internal-tracker, getting the tracker should expose that tracker's methods. In the example, the user is able to invoke log_artifact, which is specific to the wandb tracker. However, the same appears not to be working for us with the tensorboard tracker when we attempt to invoke add_images: Failing test of examples/train_unconditional.py diffusers#2468.
• The unwrap argument to get_tracker() appears not to be in use.

My question is, is the user expected to pass unwrap=True (and, therefore, there's a slight API change here), or is this being caused by some other issue? How is unwrap meant to work? The change in this PR makes it work for me, but I'm not sure if this is the intended way. Happy to dig into this further once the expectations have been clarified :)

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[muellerzr]

Yes, it's likely unwrap should be True by default, but the goal is to entice users to use the returned Accelerate tracker API instead as it handles everything. unwrap=True and the if...else... should be used if you want to grab the internal tracker, which is an API change.

Let me stew on this though, there may be something else I can do.

Edit: since the goal is to make the user have to think about if they want the internal tracking mechanism, a default of False is still what should happen :)

[muellerzr]

However, your solution Is actually perfect so going to go ahead and merge it :)