Announcing Scala.js 1.0.0-RC1

Hello everyone!

We are thrilled to announce the release of Scala.js 1.0.0-RC1!

This release candidate is intended for testing purposes by as many users as possible, and as a synchronization point with library authors so that they can start upgrading in preparation for the final release. If no critical issue is found until the end of January 2020, this RC will become the final release.

We encourage all users who are able to do so to test their projects with this RC, and report any issue as soon as possible.

As the change in “major” version number witnesses, this release is not binary compatible with 0.6.x, nor with the previous milestones of the 1.x series. Libraries need to be recompiled and republished using this RC to be compatible. Moreover, this release is not entirely source compatible with 0.6.x either.

Read all the details in the announcement on the Web:

The Scala.js team

There’s a confusing thing:

sbt 0.13.x is not supported anymore

You will not be able to use Scala.js 1.0.0-RC1 with sbt 0.13.x. You will have to upgrade to sbt 1.2.1 or later. As of this writing, the latest version is 1.3.4.

Scala 2.10.x is not supported anymore, nor building on JDK 6 and 7

The title says it all: you cannot use Scala.js with

scalaVersion := "2.10.x" // for any x

anymore. Note that you can still use the sbt plugin with sbt 0.13.17+, even though it runs itself on 2.10.x. Only the Scala.js code itself (not the build) cannot use Scala 2.10.x.

If sbt 0.13.x is not supported then why the second paragraph says that I can still use sbt plugin with sbt 0.13.17+?

1 Like

Oops, that’s a copy-paste error. Thanks for noticing the inconsistency! The second paragraph should not mention sbt anymore. There was a time where Scala 2.10.x was not supported anymore but sbt 0.13.x still was supported. Now sbt 0.13.x is not supported anymore either. I’ll fix the release notes.