build.sbt

/** Your task is to reason your way to which compiler
 *  options which will be passed for each of
 *    1) sbt root/compile
 *    2) sbt   p1/compile
 */

scalacOptions in Global                          += "-D1"
scalacOptions in ThisBuild                       += "-D0"

scalacOptions                                    := Seq("-DSBT")
scalacOptions                                    += "-D2"
scalacOptions                         in compile += "-D3"
scalacOptions              in Compile            += "-D4"
scalacOptions              in Compile in compile += "-D8"

scalacOptions in p1                              += "-D5"
scalacOptions in p1                   in compile += "-D6"
scalacOptions in p1        in Compile            += "-D7"
scalacOptions in p1        in Compile in compile += "-D9"

val root = project in file(".")
val p1   = project

//         -DSBT -D2 -D4 -D8
// -D1 -D0 -D5       -D7 -D9