Scala SBT: How to “re-run with -deprecation” (or -feature)

Scala FAQ: When compiling a Scala application with SBT, I get warning messages like these:

$ sbt compile

[warn] there were 6 deprecation warnings; re-run with -deprecation for details
[warn] there were 4 feature warnings; re-run with -feature for details

Therefore, how do I “re-run with -deprecation” or “re-run with -feature” when using SBT with Scala?


Add a line like this to your build.sbt file to see the deprecation and feature warning messages:

scalacOptions ++= Seq("-deprecation", "-feature")

If you just want to add one setting, you don’t need a Seq, just use this syntax:

scalacOptions += "-deprecation"

If you don’t want to modify your build.sbt file and just want this in your current SBT session, run this command from the SBT command line to get the same effect:

sbt> set scalacOptions in ThisBuild ++= Seq("-deprecation", "-feature")

More information

You can find more answers to questions like this in the Scala Cookbook.