Scala REPL no echo on input Ask Question

 This seems to be an issue with JLine2 being built with JDK9+, but being used on JDK8. If you're on bionic, try this PPA for jline2: https://launchpad.net/~lokkju/+archive/ubuntu/java-compat/

(or just download and install https://launchpad.net/~lokkju/+archive/ubuntu/java-compat/+build/16458066/+files/libjline2-java_2.14.6-1ubuntu1~bionicppa1_all.deb via dpkg)

You can verify jline2 is the problem by running scala -Ydebug, and looking for ByteBuffer class not found error.