We’ve decided to postpone the 2.13.0-RC1 release by 3 months (from mid October to mid January), to make sure that we have enough time to deliver the best possible upgrade experience from 2.12.7 to 2.13.0.
No major issues have come up since the last milestone, but we still feel it would be better to take some more time to resolve more of the smaller issues that remain, to improve the migration guide and the compatibility layer for cross-building between 2.12 and 2.13, and generally to help the eco-system upgrade to 2.13.0-M5 before starting the RC cycle.
Concretely, the Scala team at Lightbend is seeking to collaborate with OSS project maintainers to help port projects from 2.12 to 2.13. I’ve created a ticket to coordinate the effort – please comment there with any projects you’d like to nominate (including your own ;-)).
PS: We remain in feature freeze – this extra time is purely meant for extra polish, not more new shiny
Here’s a quick status update for the new collections library, the biggest change in 2.13: We are currently down to 47 open collection-related tickets for 2.13.0-RC1. Many of them are small issues that are not assigned yet. Contributions from the community would be especially welcome in this area.
Very few blockers remain and we believe to be on track for the scheduled release.
We have a proof of concept for the parallel collections based on the new design but some implementation work still remains to be done to port the rest of the library. We still expect to have a fully working version in time for 2.13.0.
there will be no need for an 2.13.0-M6, as we had feared
the 2.13 community build is looking strong, with as many as 83 green projects (currently lower because of small recent breaking changes, but regaining that ground won’t be hard)
Julien has completed the work on updating parallel collections, and we will publish it for RC1
We have gone through the RC1 pull request queue (16 PRs) and marked blocker tickets as “prio:blocker” (11 of 16).
Anything without the blocker label is in real danger of missing RC1. Anything with the label, we’re very eager to get done ASAP and get RC1 out the door. So there is time pressure either way.
If you could use help getting something across the finish line, blocker or not, please ask on the PR, time is running short (perhaps as little as one week).
As for the community build, thanks to community help with https://github.com/scala/bug/issues/11453, we’re up to 94 green projects now, and in addition, a number of not-yet-green projects were investigated and determined not to have uncovered Scala regressions.
Akka is the remaining community build project we want to either get green, or verify that any failures are harmless. Akka is important both as a cornerstone of a sector of the Scala ecosystem, and as a test of the viability of the new stdlib APIs that replace the scala-java8-compat module.
Lukas now has Akka compiling with the latest Scala nightly, but there are test failures that remain to be investigated.
scalajs-stubs (JVM-only) 1.0.0-RC1 for Scala 2.13.0-RC1 on its way to Maven Central.
portable-scala-reflect 0.1.0 for JVM 2.13.0-RC1, JS 0.6.x with 2.13.0-RC1 and JS 1.0.0-M7 for 2.11/2.12/2.13.0-M5/2.13.0-RC1 on their way to Maven Central.
using scala-parser-combinators 1.1.2 on Scala 2.11 may run afoul of a classpath clash between 1.1.2 and the version the Scala 2.11 compiler uses internally; see https://github.com/scala/scala-parser-combinators/issues/197 for details and workarounds
