It works in the current dev build. You have probably missing
regexp.jar in your build. Look at netbeans/lib/ext directory.

Yes, it works fine in today's development build #200210160100 of
NetBeans 4.0.

I verified and the lib/ext directory contains regexp-1.2.jar. Also,
the jar contains the missing class. But I'm still getting the
exception. I can't neither open my old projects which contain mounted
CVS filesystems. When trying to open such a project I'm getting an
exception which is pretty the same. I need to specify that I'm not
using the nightly dev build, but an own build from CVS.


java.lang.NoClassDefFoundError: org/apache/regexp/RESyntaxException
        at java.lang.Class.getDeclaredFields0(Native Method)
        at java.lang.Class.privateGetDeclaredFields(Class.java:1494)
        at java.lang.Class.getField0(Class.java:1727)
        at java.lang.Class.getDeclaredField(Class.java:1189)
        at
java.io.ObjectStreamClass.getDeclaredSUID(ObjectStreamClass.java:1430)
        at java.io.ObjectStreamClass.access$400(ObjectStreamClass.java:45)
        at java.io.ObjectStreamClass$3.run(ObjectStreamClass.java:331)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.io.ObjectStreamClass.<init>(ObjectStreamClass.java:329)
        at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:249)
        at
java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:449)
        at
java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1521)
        at
java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1435)
        at
java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1521)
        at
java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1435)
        at
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1626)
        at
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
        at
java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
        at
org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.readSerial(XMLSettingsSupport.java:488)
        at
org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.instanceCreate(XMLSettingsSupport.java:516)
        at
org.netbeans.modules.settings.convertors.SerialDataConvertor$SettingsInstance.instanceCreate(SerialDataConvertor.java:316)
        at
org.openide.loaders.FolderInstance.instanceForCookie(FolderInstance.java:365)
        at
org.netbeans.core.AutomountSupport.instanceForCookie(AutomountSupport.java:117)
        at
org.openide.loaders.FolderInstance$HoldInstance.instanceCreate(FolderInstance.java:783)
        at
org.netbeans.core.AutomountSupport.createInstance(AutomountSupport.java:82)
        at
org.openide.loaders.FolderInstance.defaultProcessObjects(FolderInstance.java:571)
        at
org.openide.loaders.FolderInstance.access$100(FolderInstance.java:45)
        at
org.openide.loaders.FolderInstance$2.run(FolderInstance.java:456)
        at org.openide.util.Task.run(Task.java:136)
[catch] at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:599)

Okay, I am gonna test the latest continuous build. If it works there
too, we can't help you. It will be probably some bug in how you build
the IDE.
Stand by ... :-)

There were massive changes in openide and in modules' manifests today
morning. org.openide.deprecated packages were introduced by Jesse
Glick and a lot of stuff from openide was moved there. I don't think,
that this should affect regex, but we will investigate it...

Confirmed as serious regression in functionality in continuous build
#20021016-0914 of NetBeans 4.0. I am rising priority since this is
definetely future Q-build showstopper. As a workaround please mount
your CVS filesystem with command-line client, however it takes ages
(nearly half a minute :-() to see the filesystem mounted into explorer
and takes 100% CPU for that period.
Thanks Leon for catching this !

It seems, that the manifest entries for Class-Path are wrong.
I don't understand why it worked. The classloader was probably more
benevolent.
I'm going to fix it...

There was missing package dependency on org.apache.regexp.* which
should be set as described at
http://www.netbeans.org/download/dev/javadoc/OpenAPIs/org/openide/doc-files/upgrade.html#3.4i-pkg-dep

Fixed in the main trunk.

In the future please add me as a CC to any bugs involving
NoClassDefFoundError's - it is probably either a bug in the module
system, or a bug in a module manifest. Either way I may be able to
offer help quickly so you don't have to spend time tracking it down.

Verified in development build #200211131011 of NetBeans 4.0.