If you have a test module called Foo you can't use Foo as the string argument to describe. And, if you do, you get a misleading error message: "The test 'Foo' contains a child test of the same name. Let's rename them so we know which is which"
Sample code:
module Foo exposing (..)
import Expect exposing (Expectation)
import Test exposing (..)
suite : Test
suite =
describe "Foo"
[ test "t1" (\_ -> 1 + 1 |> Expect.equal 2)
]
This is also discussed in #493.