investigate new 2.13 community build regressions

[SethTisue]

https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-community-build/919/consoleFull (Scala version 2.13.0-pre-79e5101) and other recent runs have:

[info] >>> The dbuild result is------------: FAILED (failed: utest, scala-continuations, akka-actor)

careful, fixing these might uncover additional failures

[SethTisue]

scala-continuations: regression reported at scala/scala-continuations#37. pulled it from the 2.13 build in scala/community-build@86972c2

[SethTisue]

the exact nature of the utest failures isn't obvious. some of them are utest.NoSuchTestExceptions, others are assertion failures involving implicit lookup.

there have indeed been changes to implicit lookup lately in 2.13, so since we're eager to get M3 out the door, I think it's a reasonably safe bet this isn't a release blocker. I've reported it upstream at com-lihaoyi/utest#149 and disabled the test suite in the community build (scala/community-build@e1ae04a)

[SethTisue]

the Akka thing looks like a regression in the interaction of @tailrec and singleton types. I've made a separate ticket on it at #467 for @milessabin to look at. I don't think this is a blocker for release, so I'll deal with it in the community build by temporarily forking Akka and removing the @tailrecs in question (scala/community-build@6ba025d)

[SethTisue]

test run: https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-community-build/921/consoleFull https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-community-build/922/consoleFull

[SethTisue]

akka-actor builds now (with the @tailrec removal), tests pass.

dbuild is giving a weird error on utest. looking into it

[utest] Retrieved from project scalacheck (commit: 9b71bb3dfe186c03292faa59976487af2ee23caa): 4 artifacts
[utest:error] scala.MatchError: f38684f7+20180129-1910 (of class java.lang.String)
[utest:error] 	at com.typesafe.dbuild.project.build.LocalBuildRunner$.prepareDepsArtifacts(LocalBuildRunner.scala:110)
[utest:error] 	at com.typesafe.dbuild.project.build.LocalBuildRunner$$anonfun$runLocalBuild$1.apply(LocalBuildRunner.scala:57)
[utest:error] 	at com.typesafe.dbuild.project.build.LocalBuildRunner$$anonfun$runLocalBuild$1.apply(LocalBuildRunner.scala:47)
[utest:error] 	at com.typesafe.dbuild.project.build.BuildDirs$.useProjectUniqueBuildDir(BuildDirs.scala:41)
[utest:error] 	at com.typesafe.dbuild.project.build.LocalBuildRunner.runLocalBuild(LocalBuildRunner.scala:47)
[utest:error] 	at com.typesafe.dbuild.project.build.LocalBuildRunner.checkCacheThenBuild(LocalBuildRunner.scala:36)

EDIT: I bet this has to do with sbt-dynver. in our fork,

> show utestJVM/version
[info] 0.6.3+11-f38684f7

I'll see if pushing a 0.6.3.1 tag pushing an empty commit and a v0.6.3.2 tag fixes it.

https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-community-build/924/consoleFull

[SethTisue]

hmm, my utest fix passes locally, fails on Jenkins. I git clean -fdxed the workspace, let's try again: https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-community-build/926/consoleFull

if this doesn't fix it, maybe I'll need to blow away ~/.dbuild

[SethTisue]

the entire build is green locally, so that means we're good to go for M3. but I'll leave this open til I get it green on Jenkins too

[SethTisue]

🍏🥝☘️✅💚

[SethTisue]

scala/community-build@3690f90 freezes all project SHAs at last used revisions until M3 is out the door