src/java.base/share/classes/jdk/internal/loader/BootLoader.java

*** 222,232 ****
  
              if (moduleName != null) {
                  // named module from runtime image or exploded module
                  Optional<Module> om = BOOT_LAYER.findModule(moduleName);
                  if (!om.isPresent())
!                     throw new InternalError();
                  return om.get();
              }
  
              return null;
          }
--- 222,232 ----
  
              if (moduleName != null) {
                  // named module from runtime image or exploded module
                  Optional<Module> om = BOOT_LAYER.findModule(moduleName);
                  if (!om.isPresent())
!                     throw new InternalError("Module not present:" + moduleName);
                  return om.get();
              }
  
              return null;
          }