Compiler hangs when cgenerator.lua errors

[distantforest1]

Bug description

The compiler hangs when running the following example:

local RTest = @record {}

function RTest:run(a: auto) -- remove: `a: auto` to see the actual error
  ## if a.type.is_niltype then
    local a = 0
  ## end
  local x: sequence(integer)
  local y

  return x, y
end

local r: RTest
r:run()

Expected behavior

Error saying any type not supported yet or something to that effect. Currently it freezes, was tough to track down since I was working on a lot of code at once (porting code from lua).

Workaround

Explicitly putting the in the type.

Environment

Provide relevant information about your environment:
Nelua 0.2.0-dev
Build number: 1615
Git date: 2024-04-20 09:45:08 -0300
Git hash: 9f75e00
Semantic version: 0.2.0-dev.1615+9f75e009
Copyright (C) 2019-2024 Eduardo Bart (https://nelua.io/)

Windows 10 x64

[edubart]

Indeed this is a bug, a shorter example is:

local function f(a: auto) local b return b end
f()

I know the cause, but not fixing soon, it's tricky, might be fixed when the language improves support for any and table types.