As of MacOS Catalina, these tweaks will no longer work, as Catalina seems to prevent the SQuirreLSQL.app package from running if squirrel-sql.sh is modified. As a workaround, I installed jenv using brew install jenv, then set the global java version using jenv global 13, where "13" is any valid JDK for SQuirrel. More info here: https://github.com/jenv/jenv