Conflicting cross-version suffixes (sbt, Scala-STM, Play-JSON)

Question

I am using a JSON extension which relies on Mandubian\'s play-json 2.2-SNAPSHOT. Everything worked fine until now I have a project based on Scala-STM. sbt reports the following

Answer 1

If you'd like to see all libraries being pulled in to your SBT project, you can use the SBT dependency graph plugin.

Using this, you can see why scala-stm is being pulled in, and also check for other conflicting scala 2.10 and 2.11 dependencies.