Sure, but I personally do not consider an exception stacktrace to be useful feedback (especially when non-developers deal with it).
I guess if a company evaluates Hudson and runs into such a situation, chances are good that it will be rejected to use...
Also this should at least be documented very well, better would be imho to let Hudson make svnkit default to the settings that most likely will work.

This is just my 2 cents, I hope you don't mind. So if this solution is sufficient to the rest of the community - okay then

Master works fine now, SLAVES NOT. I just installed Hudson 1.387 with Subversion plugin 1.21 on a newly installed RHEL5 server.

Master builds without errors.

As soon as a build is started on a slave, the following appears.

Started by user maartenvandewaarsenb
Building remotely on w7vs2010.oslo
Cleaning workspace C:\Hudson\workspace\Tryout
Checking out https://vsvn.verum.local/svn/sandbox/trunk
FATAL: Unable to locate a login configuration
java.lang.SecurityException: Unable to locate a login configuration
at com.sun.security.auth.login.ConfigFile.<init>(Unknown Source)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at javax.security.auth.login.Configuration$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.login.Configuration.getConfiguration(Unknown Source)
at javax.security.auth.login.LoginContext$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.login.LoginContext.init(Unknown Source)
at javax.security.auth.login.LoginContext.<init>(Unknown Source)
at org.tmatesoft.svn.core.internal.io.dav.http.HTTPNegotiateAuthentication.initializeSubject(HTTPNegotiateAuthentication.java:139)
at org.tmatesoft.svn.core.internal.io.dav.http.HTTPNegotiateAuthentication.needsLogin(HTTPNegotiateAuthentication.java:241)
at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:535)
at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:275)
at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:263)
at org.tmatesoft.svn.core.internal.io.dav.DAVConnection.exchangeCapabilities(DAVConnection.java:516)
at org.tmatesoft.svn.core.internal.io.dav.DAVConnection.open(DAVConnection.java:98)
at org.tmatesoft.svn.core.internal.io.dav.DAVRepository.openConnection(DAVRepository.java:1001)
at org.tmatesoft.svn.core.internal.io.dav.DAVRepository.getLatestRevision(DAVRepository.java:178)
at org.tmatesoft.svn.core.wc.SVNBasicClient.getRevisionNumber(SVNBasicClient.java:482)
at org.tmatesoft.svn.core.wc.SVNBasicClient.getLocations(SVNBasicClient.java:873)
at org.tmatesoft.svn.core.wc.SVNBasicClient.createRepository(SVNBasicClient.java:534)
at org.tmatesoft.svn.core.wc.SVNUpdateClient.doCheckout(SVNUpdateClient.java:901)
at hudson.scm.SubversionSCM$CheckOutTask.invoke(SubversionSCM.java:687)
at hudson.scm.SubversionSCM$CheckOutTask.invoke(SubversionSCM.java:604)
at hudson.FilePath$FileCallableWrapper.call(FilePath.java:1899)
at hudson.remoting.UserRequest.perform(UserRequest.java:114)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:270)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at hudson.remoting.Engine$1$1.run(Engine.java:58)
at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: Unable to locate a login configuration
at com.sun.security.auth.login.ConfigFile.init(Unknown Source)
... 40 more

Here is how I got it working on the slaves, too:

• Windows, running as service: Add -Dsvnkit.http.methods=Basic,Digest,Negotiate,NTLM to the arguments tag of the "hudson-slave.xml" in the "Remote FS root". Disconnect and restart node
• Unix, running via ssh: Add -Dsvnkit.http.methods=Basic,Digest,Negotiate,NTLM to the "JVM Options" under advanced in the node options. Disconnect and restart node

I am really not happy with all this, but at least there is a route to get it working.

Fixed toward 1.22 in rev.37344.

I've filed http://svnkit.com/tracker/view.php?id=409 in the upstream.