For type error involving inferred types, show source of the type

Consider the code:

module TestTypes where

a = 42

b = a ++ "hello"

The type Error is (ghc-8.2.1):

TestTypes.hs:3:5: error:
    • No instance for (Num [Char]) arising from the literal ‘42’
    • In the expression: 42
      In an equation for ‘a’: a = 42
  |
3 | a = 42
  |     ^^

Actually, the real mistake is in line 5, where a is inferred as of type [Char], while it was not meant to. But that location is not reported to the error. As you can guess, in real code location where the unexpected type is inferred for a binding is not that obvious to find.

Suggestion: track locations where bindings' types are inferred, and in case of type error involvin the bindings, add them to the "Relevant bindings" section, or otherwise show it.