For any properties you need to change on the command line, prepend them with "set ", and wrap them in quotes.

For your example:

sbt "set test in assembly := {}" clean assembly

For any properties you need to change on the command line, prepend them with "set ", and wrap them in quotes.

Example for Windows:

sbt "set test in assembly := {}" clean assembly

Example for Mac:

sbt 'set test in assembly := {}' clean assembly

For any properties you need to change on the command line, prepend them with "set ", and wrap them in single quotes.

For your example:

sbt 'set test in assembly := {}' clean assembly

For any properties you need to change on the command line, prepend them with "set ", and wrap them in quotes.

For your example:

sbt "set test in assembly := {}" clean assembly