scala/scala — pull request #4029 by retronym (2014-10-05 00:29:42+00:00)
Title: SI-8291 Fix implicitNotFound message with type aliases

This pattern of code is typically a bug:

if (f(tp.typeSymbol)) {
g(tp.typeArgs)
}

Intead, one needs to take the base type of `tp` wrt `tp.typeSymbol`.

This commit does exactly that when formatting the `@implicitNotFound`
custom error message.

Patch found on the back of an envelope in the handwriting of @adriaanm

Review by @som-snytt