[Java][maven] "No source code was seen and extracted"

[FizzFish]

When I compile a java project built by maven, codeql tell me "No source code was seen and extracted".

1. cmd is: codeql database create sonar.db -l java -c "./gradlew --no-build-cache clean classes"
2. The project is built correctly, and many *.class are generated.
3. There only "codeql-database.yml", "log", "working" files in codeql database directory.
   The reason is maybe that codeql cannot "Intercepted call" with Java correctly. But I don't know why codeql cannot hook Java compiler.

build-tracer.log.txt

[smowton]

Is the Gradle daemon running the compilation away from the traced process? What happens if you run the create command without passing a -c command, in which case it will by default guess a gradlew command that explicitly disables the daemon?