trec.erl:29: The call trec:mk_foo_loc
         (42,
          any()) will never return since it differs in the 1st argument from the success typing arguments: 
         ('undefined',
          atom())
trec.erl:32: Record construction violates the declared type for #foo{} since variable A cannot be of type 
          atom()
trec.erl:39: Record construction violates the declared type for #foo{} since variable A cannot be of type 
          atom()