Scala compiler/installation per project - scala-ide 4.5.0 versus 4.6.0

[Koen Daenen]

I created a fresh Scala project with Scala-IDE 4.6.0-vfinal-2017-05-16T08:49:17Z-Typesafe.

I use 'Set the Scala installation' from the menu and select: 'Fixed Scala Installation: 2.10.6 (bundle)',

which sets the scala compiler and related jar dependencies on 2.10.6.

I close the project.

I open Scala-IDE 4.5.0-vfinal-2016-12-13T10:59:29Z-Typesafe (using another workspace folder).

I import the project created as described above.

I tells me that the Scala Library container is 2.11.8.

Where is this setting stored? And is it Scala-IDE version dependent?

How do I specify the scala compiler/lib container per project consistently?

Ideally, I want to set the scalaVersion per project in sbt, and use sbteclipse to generate my eclipse project meta files.

It is not clear for me with which versions of scala-ide, the output of sbteclipse 5.1.0 is compatible with.

I've no specific requirement to use a BYO scala version in eclipse, but I do want to control which of scala version bundled

with Scala-IDE is used per project.