I am creating a multi-module sbt project, with following structure:
----build.sbt
----project
----Build.scala
----plugins.sbt
----common
-
It's just a missing import.
In .sbt files, some things are automatically imported by default: contents of objects extending Plugin, and (>= 0.13.5) autoImport fields in AutoPlugins. This is the case of PlayScala.
In a Build.scala file, normal Scala import rules apply. So you have to import things a bit more explicitly. In this case, you need to import play.PlayScala (or use .enabledPlugins(play.PlayScala) directly).