With fork := false
the following works:
sbt -Dconfig.file=alternative.conf "runMain com.test.Main"
With fork := true
the following works:
sbt '; set javaOptions += "-Dconfig.file=alternative.conf" ; runMain com.test.Main'
With fork := false
the following works:
sbt -Dconfig.file=alternative.conf "runMain com.test.Main"
With fork := true
the following works:
sbt '; set javaOptions += "-Dconfig.file=alternative.conf" ; runMain com.test.Main'