improve error message

[EstebanMarin]

For some reason found the error message was not clear on the actionable and made explicit how to change the method to take away the compiler error.

[armanbilge]

Thanks for the PR. viaTraceableValue looks like an implicit conversion so it doesn't seem like its intended to be called explicitly, so something still doesn't seem right. Would you be able to share the code you were having trouble with?

[EstebanMarin]

I cannot share the code unfortunately. Roughly is something like this

//> package natchez


/** A tracing effect, which always has a current span. */
trait Trace[F[_]] {

  /** Puts a sequence of fields into the current span. */
  def put(fields: (String, TraceValue)*): F[Unit]
somewhere in the code
Trace[F].put(", TraceValue.viaTraceableValue("string"))

Using something like TraceableValue() is not available.

However, when encountering the error I assumed there was a new .toTraceValue method in the object, but there isn't. The only available toTraceValue comes from this typeclass . After several rounds of compiler tetris I got this

TraceValue.viaTraceableValue(traceValue)

To get my migration working from < 0.3.0 to 0.3.3.

[armanbilge]

Thanks for the explanation, much appreciated. I took a closer look and I agree this deprecation message is more suitable.

However, it looks like the viaTraceableValue implicit conversion should be applied automatically, and if it's not then that's a bug that we should fix. So if you could share an example that was working before and not working after the upgrade, that would be very helpful.

[EstebanMarin]

@armanbilge I agree. that implicit conversions should be applied automatically. I would love to work on that, let me set the code to replicate the issue. I will work on this.