(how) can I use convert function?

[alxgomz]

Not sure whether that's a problem with me or a bug but here is what I'm trying to do:

I wrote a function in my bake file to compute a list of targets based on an whether an env var (MY_ VERSION) matches a list of versions:

function "exclude_if_version" {
  params = [
    versions,
    inputlist,
    excludees
    ]
  result = sethaselement(convert(versions, list(string)),"${MY_VERSION}") ? setsubtract(inputlist, excludees) : inputlist
}

As you can see above, I'd like to deal with cases where someone using that function passes numbers (e.g. [3, 4]) or string representation of the version (["3.0", "4.0"]) in the versions list.
Though when running that simple code I get the error below:

Invalid expression; function "list" does not exist: undefined

I've tried with more simple types and get the same error (e.g. convert("true", bool))

I would have expected that to work given the bake Reference states:

A set of general-purpose functions provided by go-cty are available for use in HCL files