This is really strange and disappointing, with a `nim.cfg` inside `src` folder
with just `--threads:on` inside I can, inside my "main" nim file have this line
`var thread: Thread[int]`, and it will compile but the "Hello World!" message
won't appear. If I rename the `nim.cfg` to `package_name.cfg` and remove the
`var thread: Thread[int]` line it will compile and show the hello world
message. But if I put that line again (`var thread: Thread[int]`) it won't
compile and it will show an error `Error: undeclared identifier: 'Thread'`.
