It is a major release that shouldn’t be considered binary compatible with 2.1.x,
even though it is source compatible. This is due to several operators being
changed in Observable and Task, but extension methods are provided for the older
versions, therefore source compatibility is maintained.
As a summary: the new MVar synchronization primitive, performance improvements
in Observable.concatMap and in the Task run-loop, new SchedulerService
interface for shutting down schedulers, bug fixes and upgrade to Cats 0.9.0.
See details below.
Version 2.1.1 is out now, while version 2.1.0 was out
on Nov 9.
The official announcement was then postponed because we waited to see
if bug reports are going to happen. Today version 2.1.1 was
released, fixing such a problem.
To use the new version, include this in your build.sbt (and use
%%% for Scala.js):