Scala Provider Plugin and Java 11

[Joe Shannon]

Hi all,

I am starting the process of migrating from Java 8 to Java 11 for a Gerrit instance and running into an issue with the Scala Provider Plugin:

WARN  com.google.gerrit.server.plugins.PluginLoader : Cannot load plugin xyz
scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
        at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:17)
        at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:18)

This plugin depends on Scala 2.11.6 [1]. Looking at the Scala webpage [2] it appears that 2.11.12 is the minimum version required for Java 11. Would it be possible for it to be updated?

I did attempt to clone the plugin and build it myself to verify that this would solve the issue but I am unable to build it following the instructions [3]. I'm getting:

bazel build plugins/scala-provider:scala-provider

ERROR: /tmp/repo/gerrit/plugins/scala-provider/BUILD:3:14: no such package '@scala_compiler//jar': The repository '@scala_compiler' could not be resolved and referenced by '//plugins/scala-provider:scala-provider__plugin'

Thanks,

Joe

[1] https://gerrit.googlesource.com/plugins/scripting/scala-provider/+/refs/heads/master/external_plugin_deps.bzl

[2] https://docs.scala-lang.org/overviews/jdk-compatibility/overview.html

[3] https://gerrit-review.googlesource.com/Documentation/dev-build-plugins.html