(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 target based on an env var:

function "trim_from_major" {
  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 convert in case someone uses that function passes numbers or string representation of the versions 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