SBT: publish-local to both .m2 and .ivy2, answer for https://groups.google.com/forum/?fromgroups=#!searchin/simple-build-tool/m2/simple-build-tool/BLir3V_3ajY/YQZ5vobWatoJ

Build.scala

import sbt._
import Keys._
import sbt.Classpaths.publishTask

/* code for https://groups.google.com/forum/?fromgroups=#!searchin/simple-build-tool/m2/simple-build-tool/BLir3V_3ajY/YQZ5vobWatoJ
   title: publish-local to both .m2 and .ivy2

   use "sbt pl" to publish to both local repositories
*/
object DemoBuild extends Build {

    lazy val MavenCompile = config("m2r") extend(Compile) //a configuration to set an alternative publishLocalConfiguration

    lazy val publishLocalBoth = TaskKey[Unit]("pl", "publish local for m2 and ivy")

    lazy val root = Project("hello", base = file(".")).
      settings(
        otherResolvers := Seq(Resolver.file("dotM2", file(Path.userHome + "/.m2/repository"))),

        publishLocalConfiguration in MavenCompile <<= (packagedArtifacts, deliverLocal, ivyLoggingLevel) map {
          (arts, _, level) => new PublishConfiguration(None, "dotM2", arts, Seq(), level)
        },

        publishMavenStyle in MavenCompile := true,

        publishLocal in MavenCompile <<= publishTask(publishLocalConfiguration in MavenCompile, deliverLocal),

        publishLocalBoth <<= Seq(publishLocal in MavenCompile, publishLocal).dependOn
      )
}