Multiproject SBT build bad symbolic reference scala-reflect runtime - scala

Question

I've been tasked with rewriting an old ant build script to SBT. As it happens, our suite is built up of 3 modules:
A Play 2.3 front-end webserver;
A back-end for retrieving data from various other systems;
A middle module containing some shared classes for database access and business logic.
Below an excerpt of my Build.scala file can be found:
val sharedSettings = Seq(
organization := <organization here>,
version := "1.2.5",
scalaVersion := "2.11.1",
libraryDependencies ++= libraries,
unmanagedJars in Compile ++= baseDirectory.value / "lib",
unmanagedJars in Compile ++= baseDirectory.value / "src",
unmanagedJars in Compile ++= baseDirectory.value / "test"
)
lazy val middle = project.settings(sharedSettings: _*)
lazy val back = project.settings(sharedSettings: _*).dependsOn(middle)
However, when I try to compile the source, I get the following error:
bad symbolic reference to scala.reflect.runtime encountered in class file 'ValueConverter.class'. Cannot access term runtime in package scala.reflect. The current classpath may be missing a definition for scala.reflect.runtime, or ValueConverter.class may have been compiled against a version that's incompatible with the one found on the current classpath.
The source code is organized in the following structure:
back
src
test
lib
middle
src
test
lib
front
src
test
lib
Here each lib folder contains some manually maintained libraries (which is why we want to move to sbt).
Any ideas on how to solve this?

Answer 1

In the end, I gave up on trying to get the compiler to understand the additional libraries. Eventually, I added those dependencies that were available using sbt, to the sbt managed libraries. This apparently works well.