Building a cross-build sbt project in Intellij - scala

Question

I have a sbt project with three modules A, B, Common wherein
A is compatible with scala version of 2.11.12 and depends on Common
B is compatible with scala version of 2.12.7 and depends on Common
Common can cross compile with both 2.11.12, 2.12.7 versions
To support this I have created a build.sbt as following:
import sbt._
val scalaL = "2.11.12"
val scalaH = "2.12.7"
lazy val common = (project in file("common"))
.settings(crossScalaVersions := Seq(scalaH, scalaL))
lazy val A = (project in file("A"))
.settings(scalaVersion := scalaL)
.dependsOn(common)
lazy val B = (project in file("B"))
.settings(scalaVersion := scalaH)
.dependsOn(common)
lazy val root = (project in file("."))
.aggregate(common, B, A)
.settings(crossScalaVersions := List())
I was able to update, compile this project from sbt shell by supplying the + prefix.
But when I tried building the project in Idea Intellij Ultimate 2017.3 version using the sbt project refresh option, it broke with following error:
Error while importing sbt project:
;reload; set _root_.org.jetbrains.sbt.StructureKeys.sbtStructureOptions in Global := "download resolveClassifiers" ;*/*:dumpStructureTo /tmp/sbt-structure1.xml; session clear-all
[info] Loading settings for project global-plugins from idea.sbt ...
[info] Loading global plugins from /home/bala/.sbt/1.0/plugins
[info] Loading project definition from /home/bala/ether-streaming/cross2/project
[info] Loading settings for project root from build.sbt ...
[warn] Discarding 1 session setting. Use 'session save' to persist session settings.
[info] Set current project to root (in build file:/home/bala/ether-streaming/cross2/)
[info] Defining Global / sbtStructureOptions
[info] The new value will be used by Global / ssOptions
[info] Reapplying settings...
[info] Set current project to root (in build file:/home/bala/ether-streaming/cross2/)
[info] Updating A...
[warn] module not found: common#common_2.11;0.1.0-SNAPSHOT
[warn] ==== local: tried
[warn] /home/bala/.ivy2/local/common/common_2.11/0.1.0-SNAPSHOT/ivys/ivy.xml
[warn] ==== public: tried
[warn] https://repo1.maven.org/maven2/common/common_2.11/0.1.0-SNAPSHOT/common_2.11-0.1.0-SNAPSHOT.pom
[warn] ==== local-preloaded-ivy: tried
[warn] /home/bala/.sbt/preloaded/common/common_2.11/0.1.0-SNAPSHOT/ivys/ivy.xml
[warn] ==== local-preloaded: tried
[warn] file:////home/bala/.sbt/preloaded/common/common_2.11/0.1.0-SNAPSHOT/common_2.11-0.1.0-SNAPSHOT.pom
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: UNRESOLVED DEPENDENCIES ::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: common#common_2.11;0.1.0-SNAPSHOT: not found
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn]
[warn] Note: Unresolved dependencies path:
[warn] common:common_2.11:0.1.0-SNAPSHOT
[warn] +- a:a_2.11:0.1.0-SNAPSHOT
[error] sbt.librarymanagement.ResolveException: unresolved dependency: common#common_2.11;0.1.0-SNAPSHOT: not found
[error] at sbt.internal.librarymanagement.IvyActions$.resolveAndRetrieve(IvyActions.scala:332)
[error] at sbt.internal.librarymanagement.IvyActions$.$anonfun$updateEither$1(IvyActions.scala:208)
[error] at sbt.internal.librarymanagement.IvySbt$Module.$anonfun$withModule$1(Ivy.scala:239)
[error] at sbt.internal.librarymanagement.IvySbt.$anonfun$withIvy$1(Ivy.scala:204)
[error] at sbt.internal.librarymanagement.IvySbt.sbt$internal$librarymanagement$IvySbt$$action$1(Ivy.scala:70)
[error] at sbt.internal.librarymanagement.IvySbt$$anon$3.call(Ivy.scala:77)
[error] at xsbt.boot.Locks$GlobalLock.withChannel$1(Locks.scala:93)
[error] at xsbt.boot.Locks$GlobalLock.xsbt$boot$Locks$GlobalLock$$withChannelRetries$1(Locks.scala:78)
[error] at xsbt.boot.Locks$GlobalLock$$anonfun$withFileLock$1.apply(Locks.scala:97)
[error] at xsbt.boot.Using$.withResource(Using.scala:10)
[error] at xsbt.boot.Using$.apply(Using.scala:9)
[error] at xsbt.boot.Locks$GlobalLock.ignoringDeadlockAvoided(Locks.scala:58)
[error] at xsbt.boot.Locks$GlobalLock.withLock(Locks.scala:48)
[error] at xsbt.boot.Locks$.apply0(Locks.scala:31)
[error] at xsbt.boot.Locks$.apply(Locks.scala:28)
[error] at sbt.internal.librarymanagement.IvySbt.withDefaultLogger(Ivy.scala:77)
[error] at sbt.internal.librarymanagement.IvySbt.withIvy(Ivy.scala:199)
[error] at sbt.internal.librarymanagement.IvySbt.withIvy(Ivy.scala:196)
[error] at sbt.internal.librarymanagement.IvySbt$Module.withModule(Ivy.scala:238)
[error] at sbt.internal.librarymanagement.IvyActions$.updateEither(IvyActions.scala:193)
[error] at sbt.librarymanagement.ivy.IvyDependencyResolution.update(IvyDependencyResolution.scala:20)
[error] at sbt.librarymanagement.DependencyResolution.update(DependencyResolution.scala:56)
[error] at sbt.internal.LibraryManagement$.resolve$1(LibraryManagement.scala:45)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$12(LibraryManagement.scala:93)
[error] at sbt.util.Tracked$.$anonfun$lastOutput$1(Tracked.scala:68)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$19(LibraryManagement.scala:106)
[error] at scala.util.control.Exception$Catch.apply(Exception.scala:224)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11(LibraryManagement.scala:106)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11$adapted(LibraryManagement.scala:89)
[error] at sbt.util.Tracked$.$anonfun$inputChanged$1(Tracked.scala:149)
[error] at sbt.internal.LibraryManagement$.cachedUpdate(LibraryManagement.scala:120)
[error] at sbt.Classpaths$.$anonfun$updateTask$5(Defaults.scala:2561)
[error] at scala.Function1.$anonfun$compose$1(Function1.scala:44)
[error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:40)
[error] at sbt.std.Transform$$anon$4.work(System.scala:67)
[error] at sbt.Execute.$anonfun$submit$2(Execute.scala:269)
[error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:16)
[error] at sbt.Execute.work(Execute.scala:278)
[error] at sbt.Execute.$anonfun$submit$1(Execute.scala:269)
[error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] at java.lang.Thread.run(Thread.java:748)
[error] sbt.librarymanagement.ResolveException: unresolved dependency: common#common_2.11;0.1.0-SNAPSHOT: not found
[error] at sbt.internal.librarymanagement.IvyActions$.resolveAndRetrieve(IvyActions.scala:332)
[error] at sbt.internal.librarymanagement.IvyActions$.$anonfun$updateEither$1(IvyActions.scala:208)
[error] at sbt.internal.librarymanagement.IvySbt$Module.$anonfun$withModule$1(Ivy.scala:239)
[error] at sbt.internal.librarymanagement.IvySbt.$anonfun$withIvy$1(Ivy.scala:204)
[error] at sbt.internal.librarymanagement.IvySbt.sbt$internal$librarymanagement$IvySbt$$action$1(Ivy.scala:70)
[error] at sbt.internal.librarymanagement.IvySbt$$anon$3.call(Ivy.scala:77)
[error] at xsbt.boot.Locks$GlobalLock.withChannel$1(Locks.scala:93)
[error] at xsbt.boot.Locks$GlobalLock.xsbt$boot$Locks$GlobalLock$$withChannelRetries$1(Locks.scala:78)
[error] at xsbt.boot.Locks$GlobalLock$$anonfun$withFileLock$1.apply(Locks.scala:97)
[error] at xsbt.boot.Using$.withResource(Using.scala:10)
[error] at xsbt.boot.Using$.apply(Using.scala:9)
[error] at xsbt.boot.Locks$GlobalLock.ignoringDeadlockAvoided(Locks.scala:58)
[error] at xsbt.boot.Locks$GlobalLock.withLock(Locks.scala:48)
[error] at xsbt.boot.Locks$.apply0(Locks.scala:31)
[error] at xsbt.boot.Locks$.apply(Locks.scala:28)
[error] at sbt.internal.librarymanagement.IvySbt.withDefaultLogger(Ivy.scala:77)
[error] at sbt.internal.librarymanagement.IvySbt.withIvy(Ivy.scala:199)
[error] at sbt.internal.librarymanagement.IvySbt.withIvy(Ivy.scala:196)
[error] at sbt.internal.librarymanagement.IvySbt$Module.withModule(Ivy.scala:238)
[error] at sbt.internal.librarymanagement.IvyActions$.updateEither(IvyActions.scala:193)
[error] at sbt.librarymanagement.ivy.IvyDependencyResolution.update(IvyDependencyResolution.scala:20)
[error] at sbt.librarymanagement.DependencyResolution.update(DependencyResolution.scala:56)
[error] at sbt.internal.LibraryManagement$.resolve$1(LibraryManagement.scala:45)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$12(LibraryManagement.scala:93)
[error] at sbt.util.Tracked$.$anonfun$lastOutput$1(Tracked.scala:68)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$19(LibraryManagement.scala:106)
[error] at scala.util.control.Exception$Catch.apply(Exception.scala:224)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11(LibraryManagement.scala:106)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11$adapted(LibraryManagement.scala:89)
[error] at sbt.util.Tracked$.$anonfun$inputChanged$1(Tracked.scala:149)
[error] at sbt.internal.LibraryManagement$.cachedUpdate(LibraryManagement.scala:120)
[error] at sbt.Classpaths$.$anonfun$updateTask$5(Defaults.scala:2561)
[error] at scala.Function1.$anonfun$compose$1(Function1.scala:44)
[error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:40)
[error] at sbt.std.Transform$$anon$4.work(System.scala:67)
[error] at sbt.Execute.$anonfun$submit$2(Execute.scala:269)
[error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:16)
[error] at sbt.Execute.work(Execute.scala:278)
[error] at sbt.Execute.$anonfun$submit$1(Execute.scala:269)
[error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] at java.lang.Thread.run(Thread.java:748)
[error] (A / update) sbt.librarymanagement.ResolveException: unresolved dependency: common#common_2.11;0.1.0-SNAPSHOT: not found
[error] (A / ssExtractDependencies) sbt.librarymanagement.ResolveException: unresolved dependency: common#common_2.11;0.1.0-SNAPSHOT: not found
[error] Total time: 1 s, completed 12 Dec, 2018 12:24:28 AM
From the error it is evident that it failed to resolve the 2.11 dependency of Common module while updating A. Similar error would have occurred if I would have ran update instead of + update from shell.
How can I make cross-building work in Intellij ? Or is there any existing option in Intellij to support cross-builds ?

Answer 1

I think your layout is a bit unusual, but after some experimentation I was able to come up with something which I think is acceptable. It imports into the IDE, syntax highlighting works in all modules, IDE even correctly offers 2.11 / 2.12 specific completion in the A / B parts, and builds modules as necessary.
val scalaL = "2.11.12"
val scalaH = "2.12.7"
lazy val common = (project in file("common"))
.settings(crossScalaVersions := Seq(scalaH, scalaL))
lazy val A = (project in file("A"))
.settings(scalaVersion := scalaL)
.dependsOn(common)
lazy val B = (project in file("B"))
.settings(scalaVersion := scalaH)
.dependsOn(common)
lazy val rootA = (project in file("rootA"))
.aggregate(common, A)
.settings(scalaVersion := scalaL)
lazy val rootB = (project in file("rootB"))
.aggregate(common, B)
.settings(scalaVersion := scalaH)
lazy val root = (project in file(".")).aggregate(rootA)