module java.base does not read module java.desktop

Question

When I run this test (using jmockit and TestNG, not sure if that's relevant):

public class Test {
  @Test public void test(@Mocked ProcessBuilder pb) throws IOException {
    new Expectations() {{ pb.start(); result = null; }};
    assertNull(m());
  }

  public static Process m() throws IOException {
    return new ProcessBuilder("").start();
  }
}

I get this exception:

java.lang.IllegalAccessError: class java.lang.ProcessBuilder (in module java.base) cannot access class javax.print.PrintException (in module java.desktop) because module java.base does not read module java.desktop

at java.base/java.lang.ProcessBuilder.start(ProcessBuilder.java)
....

I am using build 177.

I can rerun the test using --add-reads java.base=java.desktop argument and it works fine but I don't really understand what is happening here.

Why am I getting that exception?

module java.base does not read module java.desktop

2 Answers