Why does sbt build fail with "MissingRequirementError: object scala.runtime in compiler mirror not found."?

Question

I have this multi-module build configuration that I'm trying to get working, but whenever I try to compile the project it fails with the following error:

➜  postgresql-netty git:(multi-module) sbt clean compile
[info] Loading global plugins from /Users/mauricio/.sbt/plugins
[info] Loading project definition from /Users/mauricio/projects/scala/postgresql-netty/project
[info] Set current project to db-async-base (in build file:/Users/mauricio/projects/scala/postgresql-netty/)
[success] Total time: 0 s, completed May 1, 2013 11:18:29 PM
[info] Updating {file:/Users/mauricio/projects/scala/postgresql-netty/}db-async-common...
[info] Updating {file:/Users/mauricio/projects/scala/postgresql-netty/}db-async-base...
[info] Resolving org.specs2#scalaz-core_2.10;7.0.0 ...
[info] Done updating.
[info] Resolving org.scala-lang#scala-library;2.10.1 ...
[info] Done updating.
[info] Updating {file:/Users/mauricio/projects/scala/postgresql-netty/}postgresql-async...
[info] Resolving ch.qos.logback#logback-classic;1.0.9 ...
[info] Compiling 16 Scala sources to /Users/mauricio/projects/scala/postgresql-netty/db-async-common/target/scala-2.10/classes...
[info] Resolving org.specs2#scalaz-core_2.10;7.0.0 ...
[info] Done updating.
scala.reflect.internal.MissingRequirementError: object scala.runtime in compiler mirror not found.
    at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:16)
    at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:17)
    at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:48)
    at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40)
    at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61)
    at scala.reflect.internal.Mirrors$RootsBase.getPackage(Mirrors.scala:172)
    at scala.reflect.internal.Mirrors$RootsBase.getRequiredPackage(Mirrors.scala:175)
    at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackage$lzycompute(Definitions.scala:181)
    at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackage(Definitions.scala:181)
    at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass$lzycompute(Definitions.scala:182)
    at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass(Definitions.scala:182)
    at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr$lzycompute(Definitions.scala:1015)
    at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr(Definitions.scala:1014)
    at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses$lzycompute(Definitions.scala:1144)
    at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses(Definitions.scala:1143)
    at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode$lzycompute(Definitions.scala:1187)
    at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode(Definitions.scala:1187)
    at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1252)
    at scala.tools.nsc.Global$Run.<init>(Global.scala:1289)
    at xsbt.CachedCompiler0.run(CompilerInterface.scala:87)
    at xsbt.CachedCompiler0.run(CompilerInterface.scala:72)
    at xsbt.CompilerInterface.run(CompilerInterface.scala:27)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:73)
    at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:35)
    at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:29)
    at sbt.compiler.AggressiveCompile$$anonfun$4$$anonfun$compileScala$1$1.apply$mcV$sp(AggressiveCompile.scala:71)
    at sbt.compiler.AggressiveCompile$$anonfun$4$$anonfun$compileScala$1$1.apply(AggressiveCompile.scala:71)
    at sbt.compiler.AggressiveCompile$$anonfun$4$$anonfun$compileScala$1$1.apply(AggressiveCompile.scala:71)
    at sbt.compiler.AggressiveCompile.sbt$compiler$AggressiveCompile$$timed(AggressiveCompile.scala:101)
    at sbt.compiler.AggressiveCompile$$anonfun$4.compileScala$1(AggressiveCompile.scala:70)
    at sbt.compiler.AggressiveCompile$$anonfun$4.apply(AggressiveCompile.scala:88)
    at sbt.compiler.AggressiveCompile$$anonfun$4.apply(AggressiveCompile.scala:60)
    at sbt.inc.IncrementalCompile$$anonfun$doCompile$1.apply(Compile.scala:24)
    at sbt.inc.IncrementalCompile$$anonfun$doCompile$1.apply(Compile.scala:22)
    at sbt.inc.Incremental$.cycle(Incremental.scala:52)
    at sbt.inc.Incremental$.compile(Incremental.scala:29)
    at sbt.inc.IncrementalCompile$.apply(Compile.scala:20)
    at sbt.compiler.AggressiveCompile.compile2(AggressiveCompile.scala:96)
    at sbt.compiler.AggressiveCompile.compile1(AggressiveCompile.scala:44)
    at sbt.compiler.AggressiveCompile.apply(AggressiveCompile.scala:31)
    at sbt.Compiler$.apply(Compiler.scala:79)
    at sbt.Defaults$$anonfun$compileTask$1.apply(Defaults.scala:574)
    at sbt.Defaults$$anonfun$compileTask$1.apply(Defaults.scala:574)
    at sbt.Scoped$$anonfun$hf2$1.apply(Structure.scala:578)
    at sbt.Scoped$$anonfun$hf2$1.apply(Structure.scala:578)
    at scala.Function1$$anonfun$compose$1.apply(Function1.scala:49)
    at sbt.Scoped$Reduced$$anonfun$combine$1$$anonfun$apply$12.apply(Structure.scala:311)
    at sbt.Scoped$Reduced$$anonfun$combine$1$$anonfun$apply$12.apply(Structure.scala:311)
    at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:41)
    at sbt.std.Transform$$anon$5.work(System.scala:71)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:232)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:232)
    at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
    at sbt.Execute.work(Execute.scala:238)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:232)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:232)
    at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:160)
    at sbt.CompletionService$$anon$2.call(CompletionService.scala:30)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
[error] (db-async-common/compile:compile) scala.reflect.internal.MissingRequirementError: object scala.runtime in compiler mirror not found.
[error] Total time: 4 s, completed May 1, 2013 11:18:33 PM

Any idea what this is and how can I fix it?

Pleasing

Answer 1

Adding scala-library as a project dependency:

"org.scala-lang" % "scala-library" % "2.10.1"

Did the trick. Still not sure why this is necessary now but wasn't before.

Pleasing

I had the same problem and I fixed it by removing all extra files in my project. Not just all target/ dirs, but all project/target/ dirs as well (I think the latter was the one that solved it, and they weren't being removed by sbt clean). – Nitre

I don't think it is the right solution. The scala lib should be pulled in automatically with the version specified by scalaVersion. You should try sbt clean, then rebuild everything. – Cotswold

This solution also works with scala-maven-plugin when using JDK 9+. Just add scala-library as compile or provided scope dependency to the project. – Diplomacy

Answer 2

The issue is when you clear all the project dependencies up while setting yours, i.e. using := not ++= or += to add dependencies to libraryDependencies in a build definition, say in build.sbt:

libraryDependencies := Dependencies.microservice

With := all the current dependencies that sbt sets upfront in libraryDependencies are cleared out and the only available dependencies are these from Dependencies.microservice (as in the above example).

Adding up "org.scala-lang" % "scala-library" % "2.10.1" (or whatever version of scalaVersion you use) is just a workaround for clearing out the already-properly-initialized libraryDependencies setting.

It's easily to reproduce with the following build definition - build.sbt:

libraryDependencies := Seq()

Trying to compile Scala files results in the error - note show libraryDependencies:

➜  clear-library-dependencies  xsbt
JAVA_HOME=/Library/Java/JavaVirtualMachines/java8/Contents/Home
SBT_OPTS= -Xms512M -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled -Dfile.encoding=UTF-8
[info] Loading global plugins from /Users/jacek/.sbt/0.13/plugins
[info] Updating {file:/Users/jacek/.sbt/0.13/plugins/}global-plugins...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[info] Set current project to clear-library-dependencies (in build file:/Users/jacek/dev/sandbox/clear-library-dependencies/)
[clear-library-dependencies]> show libraryDependencies
[info] List()
[clear-library-dependencies]> compile
[info] Updating {file:/Users/jacek/dev/sandbox/clear-library-dependencies/}clear-library-dependencies...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[info] Compiling 1 Scala source to /Users/jacek/dev/sandbox/clear-library-dependencies/target/scala-2.10/classes...
[trace] Stack trace suppressed: run last compile:compileIncremental for the full output.
[error] (compile:compileIncremental) scala.reflect.internal.MissingRequirementError: object scala.runtime in compiler mirror not found.
[error] Total time: 0 s, completed Feb 3, 2015 10:36:08 PM

Change the build to the following (not usable, but just to show the point):

libraryDependencies ++= Seq()

The result's going to be as follows:

[clear-library-dependencies]> reload
[info] Loading global plugins from /Users/jacek/.sbt/0.13/plugins
[info] Set current project to clear-library-dependencies (in build file:/Users/jacek/dev/sandbox/clear-library-dependencies/)
[clear-library-dependencies]> show libraryDependencies
[info] List(org.scala-lang:scala-library:2.10.4)
[clear-library-dependencies]> compile
[info] Updating {file:/Users/jacek/dev/sandbox/clear-library-dependencies/}clear-library-dependencies...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[info] Compiling 1 Scala source to /Users/jacek/dev/sandbox/clear-library-dependencies/target/scala-2.10/classes...
[success] Total time: 1 s, completed Feb 3, 2015 10:38:19 PM

Atony

Answer 3

The thing that ended up alleviating this error for me was downgrading my java version. I recently upgraded to Java 10 which seems to have compatibility issues with some versions of scala (at the very least it has problems with scala 2.12), so moving down to Java 8 did the trick.

Feck

Answer 4

FWIW, I had a similar issue that resolved itself when I removed the .ivy2 cache for scala and restarted sbt.

Opening