fixed JPMS bug

launcher/src/main/java11/module-info.java

@@ -1,6 +1,5 @@
 module net.woggioni.envelope {
     requires java.logging;
     requires static lombok;
-    requires net.woggioni.envelope.loader;
     requires java.instrument;
 }

launcher/src/main/java11/net/woggioni/envelope/MainRunner.java

@@ -19,6 +19,7 @@ import java.net.URLClassLoader;
 
 import lombok.SneakyThrows;
 
+import net.woggioni.envelope.Constants;
 import net.woggioni.envelope.loader.ModuleClassLoader;
 import net.woggioni.envelope.loader.JarFileModuleFinder;
 import net.woggioni.envelope.loader.JarFile;
@@ -37,6 +38,14 @@ class MainRunner {
                     List<JarFile> classpath,
                     Consumer<Class<?>> runner) {
         if(mainModuleName == null) {
+            if(mainClassName == null) {
+                throw new RuntimeException(
+                        String.format(
+                                "Missing main attribute '%s' from manifest",
+                                Constants.ManifestAttributes.MAIN_CLASS
+                        )
+                );
+            }
             URL[] urls = classpath.stream().map(Launcher::getURL).toArray(URL[]::new);
             try (URLClassLoader cl = new URLClassLoader(urls, ClassLoader.getSystemClassLoader().getParent())) {
                 Thread.currentThread().setContextClassLoader(cl);
@@ -67,6 +76,7 @@ class MainRunner {
             ModuleLayer layer = controller.layer();
             Module mainModule = layer.findModule(mainModuleName).orElseThrow(
                     () -> new IllegalStateException(String.format("Main module '%s' not found", mainModuleName)));
+            Optional<String> mainClassOpt = Optional.ofNullable(mainClassName);
             runner.accept(Optional.ofNullable(mainClassName)
                 .or(() -> mainModule.getDescriptor().mainClass())
                 .map(className -> Class.forName(mainModule, className))