Error found: in module Main at tests/purs/failing/InvalidDerivedInstance2.purs:6:1 - 6:34 (line 6, column 1 - line 6, column 34) Type class instance head is invalid due to use of type    ()   All types appearing in instance declarations must be of the form T a_1 .. a_n, where each type a_i is of the same form, unless the type is fully determined by other type class arguments via functional dependencies. in type class instance    Data.Eq.Eq (Record ())   See https://github.com/purescript/documentation/blob/master/errors/InvalidInstanceHead.md for more information, or to contribute content related to this error.