ZinCompiler error org.json4s not found

I am trying to create a docker image with gatling 2.3.1

When I run the image the Zinc compilation fails with the following errors:

`

2018-05-04 07:40:14 [main] INFO io.gatling.compiler.ZincCompiler$ - ‘compiler-interface’ not yet compiled for Scala 2.12.3. Compiling…

2018-05-04 07:40:25 [main] INFO io.gatling.compiler.ZincCompiler$ - Compilation completed in 11.336 s

2018-05-04 07:40:25 [main] WARN io.gatling.compiler.ZincCompiler$ - Pruning sources from previous analysis, due to incompatible CompileSetup.

2018-05-04 07:40:25 [main] INFO io.gatling.compiler.ZincCompiler$ - Compiling 25 Scala sources to /opt/gatling/target/test-classes…

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - /opt/gatling/user-files/simulations/authorization/Compartments.scala:12: object json4s is not a member of package org

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - import org.json4s._

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - ^

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - /opt/gatling/user-files/simulations/authorization/PermissionStore.scala:8: object json4s is not a member of package org

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - import org.json4s._

2018-05-04 07:40:27 [main] ERROR io.gatling.compiler.ZincCompiler$ - ^

`

It seems like it cannot find “org.json4s” on the classpath I guess. I am actually wondering how the Zinc compiler finds libraryDependencies which are specified in build.sbt.

Does the zinc compiler even support “external” dependencies?
How can I use a library such as json4s here?

I already solved it by putting the json4s jars into the /lib folder