Remove support for -scala-output-version flag

[Kordyjan]

No description provided.

[SethTisue]

should this be milestoned for 3.2.0-RC1?

[pikinier20]

This is the report from the script that checks links stability:

Testing links stability in documentation
1990,1992c1990
< ./docs/reference/language-versions/binary-compatibility.html
< ./docs/reference/language-versions/index.html
< ./docs/reference/language-versions/source-compatibility.html
---
> ./docs/reference/language-versions.html

So basically, no pages are lost besides these that were added for -scala-output-version

[bishabosha]

This is the report from the script that checks links stability:

Testing links stability in documentation
1990,1992c1990
< ./docs/reference/language-versions/binary-compatibility.html
< ./docs/reference/language-versions/index.html
< ./docs/reference/language-versions/source-compatibility.html
---
> ./docs/reference/language-versions.html

please could we keep these pages, only some of the information in binary-compatibility.html needs to be removed

Edit: they are now kept, thanks!

[Kordyjan]

@bishabosha @julienrf
I indeed was too heavy-handed in reverting changes to the documentation. It should be better now.

[julienrf]

I only reviewed the changes that impact the reference documentation.

[Kordyjan]

@smarter @sjrd
This PR removed a private annotation from the standard library, that was used to annotate few public symbols.
Do you think this may have some significant impact on compatibility?

[sjrd]

No that will have no impact. The references to the annotation would only be found in the libraries that did define the annotation, given that it was private.

And even then, failing to resolve an annotation in existing binaries is not a hard error in the compiler.

[DavidGregory084]

Can I ask what's going on with this flag? It's being removed just after being renamed in #14606, and after work to support has begun in various projects, see e.g. com-lihaoyi/mill#1764 and sbt/sbt#6814.
Is there any discussion that I can read to catch up on these changes?

[Kordyjan]

@DavidGregory084 The flag was experimental and supported only in one milestone release of SBT. After thoroughly discussing it, we have realized that not only will it be hard to maintain, but also it can be detrimental to the ecosystem. Therefore, we have removed it.

Our communication about removing the flag and our plans for long-term compatibility for Scala 3 is in the public review phase after a few rounds of internal feedback from people from EPFL, ScalaCenter, and VirtusLab. You can find it here. I hope it will be published at the very beginning of the following week.

[DavidGregory084]

Thanks @Kordyjan I will have a read!

[SethTisue]

The blog post was published at https://www.scala-lang.org/blog/2022/08/17/long-term-compatibility-plans.html