for (DiagnosticGroup dg : diagnosticGroups) {
options.setWarningLevel(dg, CheckLevel.ERROR);
}
Compiler compiler = new Compiler();
MessageFormatter formatter =
options.errorFormat.toFormatter(compiler, false);
AntErrorManager errorManager = new AntErrorManager(formatter, task);
compiler.setErrorManager(errorManager);
Result r = compiler.compile(externs, jsInputs, options);