Default Scala version should be 2.12 (instead of 2.11)

[natansil]

Currently the default version is 2.11.12:

rules_scala/scala/scala_cross_version.bzl

Line 25 in ad41d0c

return "2.11.12"

But according to JB 2018 survey only 30% used 2.11, while 64% used 2.12

I think it's time to change the default...

[ittaiz]

I agree
@johnynek wdyt?

[johnynek]

I agree. I’d like CI to check both 2.11 and 2.12 if possible.

I assume wix is now on 2.12?

[ittaiz]

Wix is indeed on 2.12

…

On Thu, 28 Feb 2019 at 9:12 P. Oscar Boykin ***@***.***> wrote: I agree. I’d like CI to check both 2.11 and 2.12 if possible. I assume wix is now on 2.12? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#703 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABUIF4OKGJCh8yYEGeBN7Z7BQqh3BdK4ks5vR4FBgaJpZM4bVdYm> .

[igorgatis]

At least please make it easy to select, like scala_repositories(version="2.11") and scala_repositories(version="2.12")

[johnynek]

@igorgatis you have seen this right: https://github.com/bazelbuild/rules_scala#selecting-scala-version

Is it that too much?

My feeling is that repo configuration is so rarely done, this isn't a major problem.

[wisechengyi]

Twitter has also been on 2.12 for a while.

Anecdotally I worked on some scalac option related changes having incompatibilities with 2.11.x, which would be resolved if the whole repo switches to 2.12, or at least as the default.

Afacit #962 should not be blocking this and can be worked on separately if needed still, as most folks are on 2.12 already.

Is there objection to switch to 2.12 repo wide?

[smparkes]

#962 is close for now and this doesn't block it. But FWIW:

if needed still, as most folks are on 2.12 already

There's a lot of existing spark code on 2.11. For that community, there's likely to be a long tail of users so maintainers of spark libraries will likely have to support 2.11 for some time.

[ittaiz]

I agree about spark and that is why I’m happy we enabled the “test version” test on CI which gives us some sanity into 2.11