Build error: I thought a non-nullable-unwrapped variant for a lambda set was impossible

[JRI98]

The following program fails to build with error: thread 'main' panicked at 'I thought a non-nullable-unwrapped variant for a lambda set was impossible: how could such a lambda set be created without a base case?', crates/compiler/mono/src/layout.rs:1713:61 I tried to simplify it the best I could, so the program doesn't make sense.

app "hello"
    packages { pf: "https://github.com/roc-lang/basic-cli/releases/download/0.7.0/bkGby8jb0tmZYsy2hg1E_B2QrCgcSTxdUlHtETwm5m4.tar.br" }
    imports [pf.Task.{ Task }]
    provides [main] to pf

f = \list ->
    _ <- f list |> Task.await
    Task.ok {}

main =
    f []