The following command failed with:
    Error: Could not find or load main class @base_exports

${JDK9_HOME}/bin/java \
    \
    -modulepath lib:build/patches \
    \
    -addmods junit,hamcrest.core,javafx.base.test, \
    \
    @base_exports \
    \

but works when the -modulepath and -addmods are moved into the @base_exports.