svn cleanup problem

Hi,

i have problems doing svn cleanup on my sources ( svnkit 1.2.3 ), below my ant task ( groovy based ):

        antBuilder.java(classname: 'org.tmatesoft.svn.cli.SVN',
                dir: targetDir,
                fork: true) {
            antBuilder.arg(value: '--non-interactive')
            antBuilder.arg(value: 'cleanup')
            antBuilder.classpath() {
                antBuilder.pathelement(location: '${software.ant.lib.path}/svnkit.jar')
                antBuilder.pathelement(location: '${software.ant.lib.path}/svnkit-cli.jar')
                antBuilder.pathelement(location: '${software.ant.lib.path}/ganymed.jar')
            }
        }

then the output:

Fetching latest Vine source distribution
     [java] 2009-06-10 12:23:58 org.tmatesoft.svn.core.internal.util.DefaultSVNDebugLogger log

     [java] SEVERE: CLI: svn: '/Volumes/Extended/work/projects/vine-1.1/vine' is not a working copy

     [java] svn: Cannot read from '/Volumes/Extended/work/projects/vine-1.1/vine/.svn/format': /Volumes/Extended/work/projects/vine-1.1/vine/.svn/format (No such file or directory)

     [java] org.tmatesoft.svn.core.SVNException: svn: '/Volumes/Extended/work/projects/vine-1.1/vine' is not a working copy

     [java] svn: Cannot read from '/Volumes/Extended/work/projects/vine-1.1/vine/.svn/format': /Volumes/Extended/work/projects/vine-1.1/vine/.svn/format (No such file or directory)

     [java] at org.tmatesoft.svn.core.internal.wc.SVNErrorManager.error(SVNErrorManager.java:64)

     [java] at org.tmatesoft.svn.core.internal.wc.admin.SVNAdminAreaFactory.open(SVNAdminAreaFactory.java:149)

     [java] at org.tmatesoft.svn.core.internal.wc.admin.SVNWCAccess.doOpen(SVNWCAccess.java:355)

     [java] at org.tmatesoft.svn.core.internal.wc.admin.SVNWCAccess.open(SVNWCAccess.java:263)

     [java] at org.tmatesoft.svn.core.internal.wc.admin.SVNWCAccess.open(SVNWCAccess.java:256)

     [java] at org.tmatesoft.svn.core.wc.SVNWCClient.doCleanup(SVNWCClient.java:506)

     [java] at org.tmatesoft.svn.core.wc.SVNWCClient.doCleanup(SVNWCClient.java:465)

     [java] at org.tmatesoft.svn.cli.svn.SVNCleanupCommand.run(SVNCleanupCommand.java:49)

     [java] at org.tmatesoft.svn.cli.AbstractSVNCommandEnvironment.run(AbstractSVNCommandEnvironment.java:134)

     [java] at org.tmatesoft.svn.cli.AbstractSVNLauncher.run(AbstractSVNLauncher.java:81)

     [java] at org.tmatesoft.svn.cli.svn.SVN.main(SVN.java:26)

     [java] at org.tmatesoft.svn.cli.SVN.main(SVN.java:22)

     [java] svn: '.' is not a working copy

     [java] svn: Cannot read from '.svn/format': /Volumes/Extended/work/projects/vine-1.1/vine/.svn/format (No such file or directory)

     [java] Java Result: 1

     [java] Skipped '.'


Obviously, that file is not present, but my ordinary svn client does not complain about that:
svn --version
svn, version 1.6.0 (r36650)

I'd be grateful for any hints on that :)