How do dependencies work in Scala? - scala

Question

For my existing projects I am migrating from scalaVersion 2.10.5 to 2.11.7 and sbtVersion 1.13.9 also.
Current migrating project is Sales, it have Sales-common, Sales-read, Sales-write modules. It have one dependent project Core. But I don't have Core project code I have only already published artefact jars(I have myapp-core-read_2.10-2.2.33.jar, 2.10 is Scala version).
My project looks like this
Sales
common
build.sbt
read
build.sbt
write
build.sbt
build.sbt
Till now, with scala 2.10.5 everything working fine using in real time also.
After change the version I run sbt clean and sbt update. I am getting Unresolved dependency issue like this:
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: UNRESOLVED DEPENDENCIES ::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: mycompany#myapp-core-read_2.11;2.2.33: not found
[warn] :: mycomapny#myapp-core-write_2.11;2.2.33: not found
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
My Sales buld.sbt is this:
name := "myapp-sales"
organization in ThisBuild := "com.mycompany"
scalaVersion in ThisBuild := "2.11.7"
//crossScalaVersions in Thisq
//Build := List("2.10.5", scalaVersion.value)
//crossPaths := false
scalacOptions in Compile in ThisBuild ++= Seq("-unchecked", "-deprecation", "-encoding", "utf8", "-language:postfixOps", "-language:implicitConVersions")
lazy val common = Project("myapp-sales-common", file("common"))
lazy val read = Project("myapp-sales-read", file("read")).configs(IntegrationTest).settings(Defaults.itSettings: _*).dependsOn(common, write)
lazy val write = Project("myapp-sales-write", file("write")).configs(IntegrationTest).settings(Defaults.itSettings: _*).dependsOn(common)
conflictWarning in ThisBuild := ConflictWarning.disable
parallelExecution in Test in ThisBuild := false
parallelExecution in IntegrationTest in ThisBuild := false
javacOptions in Compile in ThisBuild ++= Seq("-source", "1.6", "-target", "1.6")
//Remove SNAPSHOT check from the release process (for now until Squants gets a release)
releaseProcess := releaseProcess.value.filterNot(_ == ReleaseTransformations.checkSnapshotDependencies)
My read module build.sbt:
libraryDependencies ++= Seq(
"com.mycompany" %% "myapp-core-read" % myappsales.CoreVersion % "compile", // disable using the Scala version in output paths and artifacts,
"com.mycompany" %% "myapp-core-write" % myappsales.CoreVersion % "compile",
"com.mycompany" %% "myapp-registration-common" % myappsales.RegistrationVersion % "compile",
"com.mycompany" %% "myapp-load-common" % myappsales.LoadVersion % "compile",
"com.mycompany" %% "myapp-core-write-test" % myappsales.CoreVersion % "it, test",
"com.mycompany" %% "myapp-core-test" % myappsales.CoreVersion % "it, test"
)
libraryDependencies ++= Seq(
"com.typesafe" % "config" % myappsales.TypeSafeConfigVersion % "compile",
"org.json4s" %% "json4s-native" % Versions.Json4s % "compile",
"io.spray" % "spray-routing" % Versions.Spray % "compile",
"com.typesafe.akka" %% "akka-actor" % Versions.Akka % "compile",
"com.typesafe.akka" %% "akka-remote" % Versions.Akka % "compile"
exclude ("io.netty", "netty")
)
//Assemby settings
test in assembly := {}
assemblyShadeRules in assembly := Seq(
ShadeRule.rename("play.api.libs.iteratee.**" -> "shade.play.api.libs.iteratee.#1")
.inLibrary("play" % "play-iteratees_2.10" % "2.1-RC2")
.inLibrary("org.reactivemongo" % "reactivemongo_2.10" % "0.8.1-SNAPSHOT"),
ShadeRule.rename("scala.concurrent.stm.**" -> "shade.scala.concurrent.stm.#1")
.inLibrary("org.scala-stm" % "scala-stm_2.10.0" % "0.6")
.inLibrary("play" % "play-iteratees_2.10" % "2.1-RC2")
)
assemblyMergeStrategy in assembly := {
case "application.conf" => MergeStrategy.concat
case path => MergeStrategy.defaultMergeStrategy(path)
}
//Make assembly a publishable artifact
artifact in (
Compile, assembly) := {
val art = (artifact in (Compile, assembly)).value
art.copy(`classifier` = Some("assembly"))
}
addArtifact(artifact in (Compile, assembly), assembly)
How can I make it work with existing myapp-core-read_2.10-2.2.33.jar jar?

Answer 1

Important note: Scala 2.10 and 2.11 are not binary compatible so you will have to recompile the modules on which you depend
Answer to question:
This seems to be related to how SBT resolves dependencies. When you declare a dependency like so:
"com.mycompany" %% "myapp-core-read" % myappsales.CoreVersion
The %% part in the declaration means that SBT will automatically append the scala version to the library name, so your dependency becomes
group: com.mycompany
artifactId: myapp-core-read_2.11
version: `your version`
It seems that your myapp-core-read was not compiled with scala 2.11 thus SBT can't find the correct version.
You can avoid this by using % and applying the correct suffix manually, so your dependency would become:
"com.mycompany" % "myapp-core-read_2.10" % myappsales.CoreVersion
Having said that, I think scala 2.10 and 2.11 are not binary compatible so you might have to recompile the myapp-core-read module with 2.11.