trait Build in package sbt is deprecated: Use .sbt format instead

Question

Using sbt 0.13.5, when opening the project in IntelliJ, there is a warning message

~\myproject\project\Build.scala:5: trait Build in package sbt is deprecated: Use .sbt format instead

The content of the Build.scala is

import sbt._
object MyBuild extends Build  {
  lazy val root = Project("MyProject", file("."))
    .configs(Configs.all: _*)
    .settings(Testing.settings ++ Docs.settings: _*)
}

The Appendix: .scala build definition and the sbt documentation is rather overwhelming.

How to merge my existing Build.scala to build.sbt? Would appreciate any direction to doc/tutorial/examples.

you will have to just move the content of MyBuild to an sbt file (build.sbt is the convention) — rogue-one
tried that, got confused by syntax. The Build.scala I tried to convert doesn't have the Key := Value structure as seen in the example shown in the sbt doc. — Polymerase
@SethTisue Just went ahead and upgraded to 0.13.13. All tests passed. Now just need to learn how to migrate the build.scala mentioned above into build.sbt — Polymerase

Seth Tisue Seth Tisue · Accepted Answer · 2017-02-28T18:03:45

Rename Build.scala to build.sbt and move it up one directory level, so it's at the top rather than inside the project directory.

Then strip out the beginning and end, leaving:

lazy val root = Project("MyProject", file("."))
  .configs(Configs.all: _*)
  .settings(Testing.settings ++ Docs.settings: _*)

That's the basics.

Then if you want to add more settings, for example:

lazy val root = Project("MyProject", file("."))
  .configs(Configs.all: _*)
  .settings(
    Testing.settings,
    Docs.settings,
    name := "MyApp",
    scalaVersion := "2.11.8"
  )

You don't need the :_* thing on sequences of settings anymore in sbt 0.13.13; older versions required it.

The migration guide in the official doc is here: http://www.scala-sbt.org/0.13/docs/Migrating-from-sbt-012x.html#Migrating+from+the+Build+trait

trait Build in package sbt is deprecated: Use .sbt format instead

1 Answers