more robust reset of CLASSPATH: unset variable means "." in certain situations, e.g. scalac;
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: invoke Scala within the Isabelle environment
isabelle scala_build || exit $?
classpath "$ISABELLE_SETUP_CLASSPATH"; unset ISABELLE_SETUP_CLASSPATH
classpath "$CLASSPATH"; export CLASSPATH=""
export jvm_cp_args="$(platform_path "$ISABELLE_CLASSPATH")"
export JAVA_OPTS="$ISABELLE_JAVA_SYSTEM_OPTIONS -J-Dscala.usejavacp=true"
if [ "$ISABELLE_PLATFORM_FAMILY" = "windows" ]; then
export TERM=dumb
fi
isabelle_scala scala $ISABELLE_SCALAC_OPTIONS "$@"