The following JTREG test:

    sun/tools/jstat/jstatGcCauseOutput1.sh

fails with fast debug build in nightly tests. The jstat -gccause option is tested by running with -XX:+UseSerialGC option. But the test does not expect VM to echo the -XX flag value in the output. When VM echoes the -XX options in standard output, this jstat test fails.