ByteBuffer covariant incompatibilities with Java 8 when built with Java 9 or newer

[lokkju]

On Ubuntu 18.04 with libjline2-java_2.14.16, scala, sbt, and other REPLs that use jline2 don't display user input when typed. This seems to be caused by java.nio.ByteBuffer.limit covariance under JDK9 and later. Debian/Ubuntu package maintainers build the package with JDK11 by default, resulting in bytecode incompatibility with JDK8 and lower.

This can be fixed by adding a "maven.compiler.release" property to the pom.xml, but this then prevents JDK8 from being used to build the project, so I'm not sure if this is the best solution; or if this should be considered a packaging bug. Your input on this is welcome!

Welcome to Scala 2.11.12 (OpenJDK 64-Bit Server VM, Java 1.8.0_191).
Type in expressions for evaluation. Or try :help.
Trying to instantiate an InteractiveReader from scala.tools.nsc.interpreter.jline.InteractiveReader
Trying to instantiate an InteractiveReader from scala.tools.nsc.interpreter.jline_embedded.InteractiveReader
All InteractiveReaders tried: 
  - scala.tools.nsc.interpreter.jline.InteractiveReader --> 
	java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$scala$tools$nsc$interpreter$ILoop$$instantiater$1$1.apply(ILoop.scala:858)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$scala$tools$nsc$interpreter$ILoop$$instantiater$1$1.apply(ILoop.scala:855)
	at scala.tools.nsc.interpreter.ILoop.scala$tools$nsc$interpreter$ILoop$$mkReader$1(ILoop.scala:862)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$22$$anonfun$apply$10.apply(ILoop.scala:873)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$22$$anonfun$apply$10.apply(ILoop.scala:873)
	at scala.util.Try$.apply(Try.scala:192)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$22.apply(ILoop.scala:873)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$22.apply(ILoop.scala:873)
	at scala.collection.immutable.Stream.map(Stream.scala:418)
	at scala.tools.nsc.interpreter.ILoop.chooseReader(ILoop.scala:873)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1$$anonfun$newReader$1$1.apply(ILoop.scala:893)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.newReader$1(ILoop.scala:893)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.scala$tools$nsc$interpreter$ILoop$$anonfun$$preLoop$1(ILoop.scala:897)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1$$anonfun$startup$1$1.apply(ILoop.scala:964)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:990)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:891)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:891)
	at scala.reflect.internal.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:97)
	at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:891)
	at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:74)
	at scala.tools.nsc.MainGenericRunner.run$1(MainGenericRunner.scala:87)
	at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:98)
	at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:103)
	at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
Caused by: java.lang.NoSuchMethodError: java.nio.ByteBuffer.limit(I)Ljava/nio/ByteBuffer;
	at jline.internal.InputStreamReader.<init>(InputStreamReader.java:104)
	at jline.console.ConsoleReader.setInput(ConsoleReader.java:330)
	at jline.console.ConsoleReader.<init>(ConsoleReader.java:248)
	at jline.console.ConsoleReader.<init>(ConsoleReader.java:236)
	at jline.console.ConsoleReader.<init>(ConsoleReader.java:224)
	at scala.tools.nsc.interpreter.jline.JLineConsoleReader.<init>(JLineReader.scala:64)
	at scala.tools.nsc.interpreter.jline.InteractiveReader.<init>(JLineReader.scala:33)
	... 28 more

[gnodet]

I think the same kind of trick that was used in apache/felix@2ef06ec could be used in jline.

[lokkju]

Awesome, that's probably a better fix

[lokkju]

@gnodet might you leave this open until a trick like you mentioned is implemented?