step_embed not working with parallel processing in caret about embed

[tmastny]

After more investigating, I believe the error originates here:
https://github.com/topepo/caret/blob/c69d61dd7c968b50a87fb2f337424d08ea4a980a/pkg/caret/R/train_recipes.R#L412-L413

When I debug into that line, I see that pkgs is

[1] "methods" "caret"   "recipes"

which I think means that foreach doesn't have access to embed. From ?foreach:

.packages | character vector of packages that the tasks depend on. If exrequires a R package to be loaded, this option can be used to load that package on each of the workers. Ignored when used with %do%

So I think this issue is probably a caret problem.

[topepo]

tensorflow models can't really be parallelized in the way that caret does with other models/preprocessing methods. For models using TF/keras, a check is done and the user is prohibited from running these in (non-gpu) parallel.

There's no real way to do this for recipes but I will add a note in the embed help files about this limitation.

[github-actions]

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