totally disable publishing of non-core subprojects

build.sbt

@@ -10,6 +10,15 @@ scalacOptions in ThisBuild      ++= Seq("-deprecation", "-feature")
 
 cancelable in Global := true
 
+val disablePublishing = Seq[Setting[_]](
+  publishArtifact := false,
+  // The above is enough for Maven repos but it doesn't prevent publishing of ivy.xml files
+  publish := {},
+  publishLocal := {}
+)
+
+disablePublishing  // in root
+
 lazy val core = project.in(file("core")).settings(scalaModuleSettings).settings(scalaModuleOsgiSettings).settings(
   name := "scala-parallel-collections",
   OsgiKeys.exportPackage := Seq(s"scala.collection.parallel.*;version=${version.value}"),
@@ -33,17 +42,17 @@ lazy val junit = project.in(file("junit")).settings(
   libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test",
   testOptions += Tests.Argument(TestFrameworks.JUnit, "-a", "-v"),
   fork in Test := true,
-  publishArtifact := false
+  disablePublishing
 ).dependsOn(testmacros, core)
 
 lazy val scalacheck = project.in(file("scalacheck")).settings(
   libraryDependencies += "org.scalacheck" % "scalacheck_2.12" % "1.13.4",
   fork in Test := true,
   testOptions in Test += Tests.Argument(TestFrameworks.ScalaCheck, "-workers", "1", "-minSize", "0", "-maxSize", "4000", "-minSuccessfulTests", "5"),
-  publishArtifact := false
+  disablePublishing
 ).dependsOn(core)
 
 lazy val testmacros = project.in(file("testmacros")).settings(
   libraryDependencies += scalaOrganization.value % "scala-compiler" % scalaVersion.value,
-  publishArtifact := false
+  disablePublishing
 )