Display errors generated when inlining fails implicit search

[bishabosha]

When a given instance is generated by a macro and the macro fails, it would be useful to see which errors were generated in expansion, rather than only see the method that was attempted.

Minimized code

class FailHere

trait TC[T]
object TC {

  inline def mkDefaultTC[A]: TC[A] = inline compiletime.erasedValue[A] match {
    case _: FailHere => compiletime.error("blow up here")
    case _           => ???
  }

  inline given [T]: TC[T] = mkDefaultTC[T]
}

def test =
  summon[TC[Int]] // ok
  summon[TC[FailHere]] // error: no implicit argument of type TC[FailHere] was found
  TC.mkDefaultTC[FailHere] // error: blow up here

Output

-- Error: sandbox/mirror/example.scala:16:22 -----------------------------------
16 |  summon[TC[FailHere]] // error: no implicit argument of type TC[FailHere] was found
   |                      ^
   |no implicit argument of type TC[FailHere] was found for parameter x of method summon in object Predef.
   |I found:
   |
   |    TC.given_TC_T[FailHere]
   |
   |But method given_TC_T in object TC does not match type TC[FailHere].
-- Error: sandbox/mirror/example.scala:17:16 -----------------------------------
17 |  TC.mkDefaultTC[FailHere] // error: blow up here
   |  ^^^^^^^^^^^^^^^^^^^^^^^^
   |  blow up here
2 errors found

Expectation

I would also like to see the "blow up here" error for summon[TC[FailHere]], for example, we already see that given_TC_T was attempted so maybe the error can say that But method given_TC_T failed with errors: ...

[nicolasstucki]

This might be fixed by #9984. See https://github.com/lampepfl/dotty/pull/9984/files#diff-682cdfd833686fd57486c36d95f76e064006935841d14726a2c4e87f06589ac4R1-R4