For example:

$ sjavac --state-dir=bin -src src -d bin --server:portfile=portfile --log-level=debug --compare-found-sources make-file-list
java.lang.IllegalArgumentException: invalid flag: --log-level=debug
at com.sun.tools.javac.main.Arguments.error(Arguments.java:611)
at com.sun.tools.javac.main.Arguments.doProcessArgs(Arguments.java:367)
at com.sun.tools.javac.main.Arguments.processArgs(Arguments.java:285)
at com.sun.tools.javac.main.Arguments.init(Arguments.java:239)
at com.sun.tools.javac.api.JavacTool.getTask(JavacTool.java:167)
at com.sun.tools.sjavac.PubApiExtractor.<init>(PubApiExtractor.java:64)
at com.sun.tools.sjavac.JavacState.taintPackagesDependingOnChangedClasspathPackages(JavacState.java:530)
at com.sun.tools.sjavac.comp.SjavacImpl.compile(SjavacImpl.java:220)
at com.sun.tools.sjavac.comp.PooledSjavac.lambda$compile$0(PooledSjavac.java:61)
at com.sun.tools.sjavac.comp.PooledSjavac$$Lambda$3/2104546693.call(Unknown Source)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)