2.13.0-M5 release train


the JARs on Maven Central seem fine…

…but for distribution bundles, we’re delayed waiting for the replaced files on S3 to show up in all locales, and then get propagated through the Travis-CI -> chara -> scala-lang.org chain. so we won’t officially announce until that’s finished (later today? tomorrow? knock on wood)


Support for 2.13.0-M5 has been merged in Scala.js. We’ve started our own release train for 0.6.25 to make that support available. Assuming everything goes smoothly, jars will be available sometime tomorrow, although an official announcement will probably wait until Monday.

We’re not very happy about our process. The 2.13.x cycle has put enormous pressure on Scala.js to keep up and be released in a timely manner. We had to actively reduce our quality standards in terms of review process to make both M4 and M5. In both cases, changes merged in 2.13.x up to a few days or even the very same day as the release were source-breaking for Scala.js. Normally, we’re able to back-published already released versions of Scala.js when milestones of Scala show up, but that was far from being true for 2.13.0-M4 and M5.

I very much hope that the fast pace of 2.13.x is winding down, and that future milestones/RCs will be backward source compatible for Scala.js. In the future, I would like to ask for a bit more consideration for the ecosystem: allow for a few weeks between the last merges of source-breaking changes and the release of a milestones. That way, there is a chance that we don’t need to make changes, PR, review, merge, and deploy all within a few days, which is detrimental to our quality standards.


Scala 2.13.0-M5 is fully released and announced https://twitter.com/scala_lang/status/1035227635784212481


That’s very reasonable, and I’m sorry we haven’t been more proactive in coordinating with you! I agree there should be more time between last merged PR and staging the release, and again between staging and actually publishing.

We definitely want to slow things down for the RC cycle, which will start in 6 weeks, and will have RCs every two-three weeks. We intend to spend a significant amount of time helping more of the eco system upgrade, so we may end up delaying the RCs as necessary.

At least that’s the current plan. Let’s discuss!


Scala.js 0.6.25 is en route to Maven Central. Supports 2.10 through 2.12 as usual, plus 2.13.0-M3, M4 and M5.

Official announcement with release notes etc. to follow. For now, I announce it only here mostly for libraries blocked on Scala.js to publish their 2.13.0-M5 version.


I’ve just published macro-compat 1.1.1 for 2.13.0-M5 JVM/JS.


We’ve published scala-collection-compat 0.2.0 for 2.13.0-M5 (JVM/JS).


I’ve just published shapeless 2.3.3 for 2.13.0-M5 JVM/JS.


published: scala-xml 1.1.0, scala-parser-combinators 1.1.1, scala-collection-compat 0.2.0

see https://github.com/scala/make-release-notes/blob/2.13.x/projects-2.13.md for full list


more M5 libs available: scalacheck 1.14.0, scala-java8-compat 0.9.0, utest 0.6.6, genjavadoc 0.11, kind-projector 0.9.8, more.

see https://github.com/scala/make-release-notes/blob/2.13.x/projects-2.13.md for full list

with ScalaCheck now published as of a few days ago, that frees up ScalaTest and Specs2 to publish next, and then that should unblock many downstream projects.


note that ScalaCheck published for JVM only, so some downstream projects are still waiting for a Scala.js artifact to follow.

ScalaTest has now published (3.0.6-SNAP3), but also JVM only for now.


ScalaCheck and ScalaTest have both now published for both JVM and JS.

Specs2 (4.3.5) is published for JVM, but JS publishing is still pending (https://github.com/etorreborre/specs2/issues/709).

some other libraries now available for M5: expecty, scalaprops, json4s, unfiltered, et al. see https://github.com/scala/make-release-notes/blob/2.13.x/projects-2.13.md for full list


Specs2 4.3.5 is now available for both JVM & JS

Scala.js 1.0.0-M6 has been released, and supports M5 (so does 0.6.25, as before)

a bug was found in ScalaTest 3.0.6-SNAP3, fixed in SNAP4


Slinky 0.5.1+2-1405886d onwards is now published for 2.13.0-M5!


more libraries have been published for M5: cats, monocle, twirl, ssl-config, refined, catalysts, airframe, scoverage, scala-logging, minitest, scalate, simulacrum, enumeratum, machinist, discipline

see https://github.com/scala/make-release-notes/blob/2.13.x/projects-2.13.md for full list, and/or consult Scaladex and/or search.maven.org


better-files is now released for 2.13.0-M5


other projects that have published for M5 recently: cats-effect, scala-stm, scala-java-time, sourcecode, play-doc, play-json, better-monadic-for


Akka 2.5.19 (including actor, stream, cluster etc) is now also released for -M5, though accompanying libraries (such as akka-http, akka-management, akka-grpc etc) are still pending.


very great!


now available for M5: circe, scala-async, scopt