cannot initialize Look and Feel: com.sun.java.swing.plaf.gtk.GTKLookAndFeel
error: java.lang.ClassNotFoundException: com.sun.java.swing.plaf.gtk.GTKLookAndFeel not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:opengrok.jar], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}
java.lang.ClassNotFoundException: com.sun.java.swing.plaf.gtk.GTKLookAndFeel not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:opengrok.jar], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}
   at java.net.URLClassLoader.findClass(libgcj.so.70)
   at gnu.gcj.runtime.SystemClassLoader.findClass(libgcj.so.70)
   at java.lang.ClassLoader.loadClass(libgcj.so.70)
   at java.lang.ClassLoader.loadClass(libgcj.so.70)
   at java.lang.Class.forName(libgcj.so.70)
   at javax.swing.UIManager.setLookAndFeel(libgcj.so.70)
   at javax.swing.UIManager.<clinit>(libgcj.so.70)
   at java.lang.Class.initializeClass(libgcj.so.70)
   at javax.swing.UIManager.getDefaults(libgcj.so.70)
   at javax.swing.JFrame.frameInit(libgcj.so.70)
   at javax.swing.JFrame.<init>(libgcj.so.70)
   at org.opensolaris.opengrok.search.scope.MainFrame.<init>(MainFrame.java:72)
   at org.opensolaris.opengrok.search.scope.MainFrame$18.run(MainFrame.java:753)
   at java.awt.event.InvocationEvent.dispatch(libgcj.so.70)
   at java.awt.EventQueue.dispatchEvent(libgcj.so.70)
   at java.awt.EventDispatchThread.run(libgcj.so.70)
falling back to Metal Look and Feel