java.lang.NullPointerException in project root running sbt

Question

I'm starting in Scala and I'm trying to run sbt in my project folder where build.sbt is. This folder is the only one when I get this error. If I run it in the src folder or in my Documents folder I don't get the error. Could anyone tell me why is this happening? I wouldn't know how to represent the folder structure, it would be the main root with the build.sbt and inside the src folder would be example/src/main/scala/example/Lists.scala. It is a folder from coursera so I didn't create it. The build is :

name := course.value + "-" + assignment.value

scalaVersion := "2.11.7"

scalacOptions ++= Seq("-deprecation")

// grading libraries
libraryDependencies += "junit" % "junit" % "4.10" % Test

// for funsets
libraryDependencies += "org.scala-lang.modules" %% "scala-parser-combinators" % "1.0.4"

// include the common dir
commonSourcePackages += "common"

courseId := "bRPXgjY9EeW6RApRXdjJPw" 

The error is:

java.lang.NullPointerException
    at java.base/java.util.regex.Matcher.getTextLength(Matcher.java:1769)
    at java.base/java.util.regex.Matcher.reset(Matcher.java:416)
    at java.base/java.util.regex.Matcher.<init>(Matcher.java:253)
    at java.base/java.util.regex.Pattern.matcher(Pattern.java:1147)
    at java.base/java.util.regex.Pattern.split(Pattern.java:1264)
    at java.base/java.util.regex.Pattern.split(Pattern.java:1335)
    at sbt.IO$.pathSplit(IO.scala:744)
    at sbt.IO$.parseClasspath(IO.scala:859)
    at sbt.compiler.CompilerArguments.extClasspath(CompilerArguments.scala:62)
    at sbt.compiler.MixedAnalyzingCompiler$.withBootclasspath(MixedAnalyzingCompiler.scala:189)
    at sbt.compiler.MixedAnalyzingCompiler$.searchClasspathAndLookup(MixedAnalyzingCompiler.scala:167)
    at sbt.compiler.MixedAnalyzingCompiler$.apply(MixedAnalyzingCompiler.scala:177)
    at sbt.compiler.IC$.incrementalCompile(IncrementalCompiler.scala:138)
    at sbt.Compiler$.compile(Compiler.scala:128)
    at sbt.Compiler$.compile(Compiler.scala:114)
    at sbt.Defaults$.sbt$Defaults$$compileIncrementalTaskImpl(Defaults.scala:829)
    at sbt.Defaults$$anonfun$compileIncrementalTask$1.apply(Defaults.scala:820)
    at sbt.Defaults$$anonfun$compileIncrementalTask$1.apply(Defaults.scala:818)
    at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
    at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
    at sbt.std.Transform$$anon$4.work(System.scala:63)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
    at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
    at sbt.Execute.work(Execute.scala:235)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
    at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
    at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:514)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.base/java.lang.Thread.run(Thread.java:844)
[error] (compile:compileIncremental) java.lang.NullPointerException
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Answer 1

Your issue may be an old SBT version.

Ensure you are using SBT 0.13.17+ for JDK 9 compatibility (i.e. by setting sbt.version=0.13.17 in your project/build.properties)

reference: https://github.com/sbt/sbt/pull/3848