2.12-ification

In order to support 2.12, we need to add crossScalaVersions to Build.scala, and make sure everything compiles. Not every scala library will be built against the current snapshot, so we may have to support different versions from 2.11 to 2.12. If part of an API has churned (scalacheck in particular is susceptible to this) we may need to upgrade the 2.11 library version to make progress. If that happens, contact me (@mosesn) and I’ll navigate the upgrade for you–it’s a little complicated because we will need to upgrade all of our internal libraries, not just finagle.

I expect most of the modules to be straightforward to upgrade. The one that might not be is util-eval, which we still can’t get rid of because ostrich depends on it. I’ll see if I can remove it from ostrich, but I’m not holding my breath.

• util-app @jeffreyolchovy https://github.com/twitter/util/pull/163
• util-benchmark @jeffreyolchovy
• util-cache @jeffreyolchovy
• util-class-preloader @jeffreyolchovy
• util-codec @jeffreyolchovy
• util-collection @jeffreyolchovy
• util-core @jeffreyolchovy
• util-eval @jeffreyolchovy
• util-events @jeffreyolchovy
• util-function @jeffreyolchovy
• util-hashing @jeffreyolchovy
• util-jvm @jeffreyolchovy
• util-lint @jeffreyolchovy
• util-logging @jeffreyolchovy
• util-reflect @jeffreyolchovy
• util-registry @jeffreyolchovy
• util-stats @jeffreyolchovy
• util-test @jeffreyolchovy
• util-thrift @jeffreyolchovy
• util-zk @jeffreyolchovy
• util-zk-common @jeffreyolchovy
• util-zk-test @jeffreyolchovy

If you want to claim a module, please let us know in this thread! I’ll annotate different modules once they’re done.

Probably a good way to start is for someone to try add 2.12 support for all of them, and then report back which ones still fail, so we know which ones are tricky and which ones work trivially.

[idarlington]

ok cool, got it. I would take ostrich. Thanks @jeffreyolchovy

[mosesn]

@stuhood @jeffreyolchovy I filed https://issues.scala-lang.org/browse/SI-9796 to see if the scala folks can help figure out the type inference regression we found in Witness. I think it somehow has to do with traits which have only one method–I think they might be compiled down to java functions under the hood.