Cannot use the released nif version

[lud-wj]

EDIT Sorry this seems to be fixed already. I did not check the version used by meeseeks. I'l let this open in case there was a slight difference in the problem, but close at will :)

Hello,

I'm trying to use an Elixir library (meeseeks_html5ever) that only publishes nif-2.15 releases.

But my nif version is 2.17, and rustler precompiled

  use RustlerPrecompiled,
    nif_versions: ~w(2.15),

But then I have this error:

** (RuntimeError) precompiled NIF is not available for this NIF version: "2.16".
The available NIF versions are:
 - 2.15

So I dug and found the following code:

  def find_compatible_nif_version(vsn, available) do
   if vsn in available do
     {:ok, vsn}
   else
     [major, minor | _] = parse_version(vsn)

     available
     |> Enum.map(&parse_version/1)
     |> Enum.filter(fn
       [^major, available_minor | _] when available_minor <= minor -> true
       [_ | _] -> false
     end)
     |> case do
       [] -> :error
       match -> {:ok, match |> Enum.max() |> Enum.join(".")}
     end
   end
 end

So this will select "2.16" only, although I configured my versions to ["2.15"].

The problem is that target_config/0 will pass the hardcoded list of all available versions in find_compatible_nif_version(current_nif_version, Config.available_nif_versions()), instead of reducing that list to what I configured.

A very simple fix would be to call case target(target_config(config.nif_versions), config.targets, config.nif_versions) do,

With this signatures: defp target_config(available_nif_versions \\ Config.available_nif_versions()) do

And in there, that call: find_compatible_nif_version(current_nif_version, available_nif_versions)

So I can make a PR but is there a reason not to make this change?

Thank you.