How to change log level from command line?

Question

How can I change the log level in sbt at the command line without modifying the existing configuration?

Answer 1

For SBT 0.12:

If you want to change the log level from the command line, you may do in sbt interactive mode without changing your build.sbt file or any configuration. Just type:

> set logLevel := Level.Debug

However if you are writing some scripts that will run in your server and you can't do interactively, you will have to create a boot.properties file setting the desired log level and pass this file in the command line, by running

sbt -Dsbt.boot.properties=path-to-your-boot.properties

Check the documentation for boot.properties here