src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java

*** 72,81 ****
--- 72,82 ----
  import java.util.Map;
  import java.util.MissingResourceException;
  import java.util.Optional;
  import java.util.ResourceBundle;
  import java.util.Set;
+ import java.util.TreeSet;
  import java.util.function.Consumer;
  import java.util.function.Function;
  import java.util.function.Predicate;
  import java.util.function.Supplier;
  import java.util.jar.JarEntry;
*** 495,504 ****
--- 496,506 ----
              try (InputStream in = miSupplier.get()) {
                  ModuleInfoExtender extender = ModuleInfoExtender.newExtender(in);
  
                  // Add (or replace) the Packages attribute
                  if (packages != null) {
+                     validatePackages(descriptor, packages);
                      extender.packages(packages);
                  }
  
                  // --main-class
                  if (mainClass != null)
*** 528,537 ****
--- 530,557 ----
                  // write the (possibly extended or modified) module-info.class
                  out.writeEntry(extender.toByteArray(), Section.CLASSES, MODULE_INFO);
              }
          }
  
+         private void validatePackages(ModuleDescriptor descriptor, Set<String> packages) {
+             Set<String> nonExistPackages = new TreeSet<>();
+             descriptor.exports().stream()
+                 .map(Exports::source)
+                 .filter(pn -> !packages.contains(pn))
+                 .forEach(nonExistPackages::add);
+ 
+             descriptor.opens().stream()
+                 .map(Opens::source)
+                 .filter(pn -> !packages.contains(pn))
+                 .forEach(nonExistPackages::add);
+ 
+             if (!nonExistPackages.isEmpty()) {
+                 throw new CommandException("err.missing.export.or.open.packages",
+                     descriptor.name(), nonExistPackages);
+             }
+         }
+ 
          /*
           * Hasher resolves a module graph using the --hash-modules PATTERN
           * as the roots.
           *
           * The jmod file is being created and does not exist in the