Code duplication measure doesn't work

[jaksky]

Hello,

this is more question than issue as I am new to sonar with scala. While I was using java all just magically worked out of the box.
Code duplication measure doesn't work or it displays constantly 0.
I think that root cause is here:

INFO: Sensor CPD Block Indexer
INFO: DefaultCpdBlockIndexer is used for scala
INFO: Sensor CPD Block Indexer (done) | time=1ms
INFO: Calculating CPD for 0 files

Am I missing some configuration option here?
When using PMD CPD reports gets generated fine I just don't know if that gets uploaded to sonar.