reconsider removal of -Yno-adapted-args in 2.13

[SethTisue]

I'm confused why -Yno-adapted-args got the axe (in scala/scala#6505, under the umbrella of
scala/scala-dev#430)

might this have been overzealous? -Yno-adapted-args is both widely used and useful IMO

and it only causes "language fragmentation" in the sense that it makes some code — code that has been producing compiler warnings since Scala 2.11 (EDIT: under -Xlint, that is, not by default) — give a hard error instead of a warning

if we were to get rid of argument adaptation entirely, as I expect to happen in Scala 2.14 and/or Scala 3, then it will make sense to remove the flag at that time. but I don't see that it makes sense to remove now

[Jasper-M]

and it only causes "language fragmentation" in the sense that it makes some code — code that has been producing compiler warnings since Scala 2.11 — give a hard error instead of a warning

There doesn't seem to be a warning without the flag, though.

[hrhino]

You need to use -Ywarn-adapted-args for the warning, which apparently made the cut, so that and -Xfatal-warnings have a similar effect in conjunction.

That said, I always turn on -Yno-adapted-args in my project, and I'll be sad to see it go. (Isn't there talk of removing it completely in Dotty?)

[dwijnand]

Duplicate of scala/scala-dev#496, I'd say.

[SethTisue]

(Isn't there talk of removing it completely in Dotty?)

yes, this "feature" is on its slow way out of existence.

You need to use -Ywarn-adapted-args for the warning

ah, right, thanks for the correction. note that this warning has been part of -Xlint since 2.11, though, so it hasn't been only behind that one obscure flag.

Duplicate of scala/scala-dev#496, I'd say.

I see your point, but that one's targeted for 2.13.1. I opened this ticket specifically to ask what we're going to do for 2.13.0-RC1/2.13.0, since changes have already been made in this area in the milestones.

[dwijnand]

I think that one should target RC1.

[adriaanm]

For migration to dotty, we can adjust adaption use -Xsource. Since we're out of time for RC1, re-scheduling for 2.13.1. If someone manages to fix this for the RC1, that's fine too, but we won't hold up the RCs for this.

[SethTisue]

@szeiger's Scala Days talk has a slide on this. from https://downloads.lightbend.com/website/scaladays/2018/ny/slides/migrating-to-scala-2-13.pdf