IntelliJ cannot resolve symbol in build.sbt

Question

IntelliJ IDEA 15 is reporting an unresolved symbol for my project definition in my build.sbt file

lazy val root = (project in file(".")).enablePlugins(PlayScala)

It's reporting an error with project and in.

Cannot resolve symbol project.
Cannot resolve symbol in.

Everything else resolves perfectly and the project is otherwise all set up, sbt builds fine, activator runs fine.

Answer 1

I had an issue with http references in my ~/sbt/repositories file. When I changed this to https all was well.

typesafe-releases: https://repo.typesafe.com/typesafe/releases
typesafe-ivy-releasez: https://repo.typesafe.com/typesafe/ivy-releases, [organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext]

Answer 2

In my case, after upgrading Intellij forgot that the project was a Scala project.

Delete .idea/ and import the project to fix this.

Answer 3

To fix this issue, I imported: import sbt.project on top of my build.sbt

I am working with IntelliJ IDEA 16 EAP

Answer 4

This happened to me when when the "external library" referenced was a different version than the one stated in the build.sbt file. Specifically:

External Libraries -> SBT: org.scala-lang:scala-library:2.12.1

build.sbt -> scalaVersion := "2.12.2"

Answer 5

I looked on jetbrains' error tracker and found this is a known bug.

"Cannot resolve symbol project" in build.sbt

https://youtrack.jetbrains.com/issue/SCL-9512