It doesn't report them immediately.

```
% scalac-hash v2.11.0-M7 -Ylog:typer -Ydebug test/files/pos/t8219.scala 2>&1 | grep update
[log typer] update buffer: Vector([Type error at:NoPosition] type mismatch;
```

```scala
    if (result.isFailure && saveAmbiguousDivergent && implicitSearchContext.hasErrors) {
      context.updateBuffer(implicitSearchContext.reportBuffer.errors.collect {
        case dte: DivergentImplicitTypeError => dte
        case ate: AmbiguousImplicitTypeError => ate
      })
      debuglog("update buffer: " + implicitSearchContext.reportBuffer.errors)
    }
```

I'm going to try a slightly different approach with `saveErrors = false`.