Known JDK9 Problems

ASM included in Gradle no longer works with JDK9 Build 119.
You need a change similar to
— org/objectweb/asm/ClassReader.java
@@ -195,7 +195,7 @@
// checks the class version

  •    if (readShort(off + 6) > Opcodes.V1_8) { 
    
  •    if (readShort(off + 6) > Opcodes.V1_9) { 
    

— org/objectweb/asm/Opcodes.java
@@ -87,6 +87,7 @@
int V1_8 = 0 << 16 | 52;

  • int V1_9 = 0 << 16 | 53;
    .

Also still waiting for removal of internal Java class references.
java.base/sun.net.www.protocol.file.FileURLConnection
java.base/sun.net.www

Also, Gradle uses @argfile to pass arguments. If the application uses @argfile, then you end up with a nested argument file, which is not supported. One way to handle this is for Gradle to read the application argument file and copy into the Gradle argument file.