T15076.hs:13:11: warning: [-Wpartial-type-signatures (in -Wdefault)]
    • Found type wildcard ‘_’ standing for ‘Proxy f’
      Where: ‘f’, ‘a’ are rigid type variables bound by
               the type signature for:
                 foo :: forall a (f :: forall (x :: a). Proxy x -> *). Proxy f -> ()
               at T15076.hs:(10,1)-(12,20)
    • In a pattern type signature: _
      In the pattern: _ :: _
      In an equation for ‘foo’: foo (_ :: _) = ()
    • Relevant bindings include
        foo :: Proxy f -> () (bound at T15076.hs:13:1)