[3.0.x] Scala 2.13.14 / Add explicit types and remove -Xmigration flag

[mkurz]

Waiting for official announcement:

• https://github.com/scala/scala/releases/tag/v2.13.14
• https://contributors.scala-lang.org/t/scala-2-13-14-release-planning/6581/13
• https://github.com/SethTisue/scala-dev/blob/scala-2.13.14/releases/2.13.14.md
  • from Scala 2.13.14 draft release notes scala/scala-dev#869

[mkurz]

@SethTisue Solely changing the Scala version from 2.13.13 to 2.13.14 results in following errors, see https://github.com/playframework/playframework/actions/runs/8895002546/job/24424731331?pr=12576#step:11:384:

[error] /home/runner/work/playframework/playframework/core/play-streams/src/main/scala/play/api/libs/streams/ActorFlow.scala:59:24: in Scala 3 (or with -Xsource-features:infer-override), the inferred type changes to org.apache.pekko.actor.SupervisorStrategy instead of org.apache.pekko.actor.OneForOneStrategy [quickfixable]
[error] Scala 3 migration messages are issued as errors under -Xsource:3. Use -Wconf or @nowarn to demote them to warnings or suppress.
[error] Applicable -Wconf / @nowarn filters for this fatal warning: msg=<part of the message>, cat=scala3-migration, site=play.api.libs.streams.ActorFlow.actorRef
[error]           override def supervisorStrategy = OneForOneStrategy() {
[error]                        ^
[info] done compiling
[error] (ProjectRef(uri("file:///home/runner/work/playframework/playframework/"), "Play-Streams") / Compile / compileIncremental) Compilation failed

....

[error] /home/runner/work/playframework/playframework/core/play-configuration/src/main/scala/play/api/Configuration.scala:161:15: in Scala 3 (or with -Xsource-features:infer-override), the inferred type changes to Integer instead of Null [quickfixable]
[error] Scala 3 migration messages are issued as errors under -Xsource:3. Use -Wconf or @nowarn to demote them to warnings or suppress.
[error] Applicable -Wconf / @nowarn filters for this fatal warning: msg=<part of the message>, cat=scala3-migration, site=play.api.Configuration.configError.$anonfun
[error]           def position          = null
[error]               ^
[error] one error found
[error] one error found
[error] (ProjectRef(uri("file:///home/runner/work/playframework/playframework/"), "Play-Configuration") / Compile / compileIncremental) Compilation failed

Is this expected?

[lrytz]

Ah, you're using -Xsource:3 -Xmigration on the 3.0.x branch (https://github.com/playframework/playframework/blob/3.0.x/project/PlayBuildBase.scala#L59). That was a sort of a secret shorthand for -Xsource:3 -Wconf:cat=scala3-migration:w in 2.13.13 only, which we removed...