Target compileJava15Java seems to be a strange mixture of Java versions 15, 11, and 17...
compileJava15Java {
sourceCompatibility = 11
targetCompatibility = 11
options.fork = true
options.forkOptions.executable = "${System.getenv("JAVA_17_HOME")}/bin/javac.exe"
options.forkOptions.javaHome = file("${System.getenv("JAVA_17_HOME")}")
options.compilerArgs.addAll(['--add-exports', 'java.base/jdk.internal.reflect=ALL-UNNAMED', '--add-exports', 'java.base/jdk.internal.perf=ALL-UNNAMED'])
}