IOException: Could not delete file /tmp/forgetemp...

Trying to install a plugin from a git repositoy, with the command:
forge git-plugin git://github.com/bleathem/richfaces-forge-plugin.git

I get the error:
**ERROR** [forge git-plugin] Could not delete file /tmp/forgetemp4740532537388554878/repo/.git/objects/incoming_7012870980931945616.idx

Setting VERBOSE = true I get the stack trace:
org.jboss.seam.forge.shell.exceptions.CommandExecutionException: Could not delete file /tmp/forgetemp4740532537388554878/repo/.git/objects/incoming_7012870980931945616.idx
at org.jboss.seam.forge.shell.command.Execution.perform(Execution.java:143)
at org.jboss.seam.forge.shell.command.fshparser.FSHRuntime.run(FSHRuntime.java:125)
at org.jboss.seam.forge.shell.command.fshparser.FSHRuntime.run(FSHRuntime.java:63)
at org.jboss.seam.forge.shell.ShellImpl.execute(ShellImpl.java:677)
at org.jboss.seam.forge.shell.ShellImpl.doShell(ShellImpl.java:493)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.weld.bean.proxy.AbstractBeanInstance.invoke(AbstractBeanInstance.java:48)
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:125)
at org.jboss.seam.forge.shell.org$jboss$weld$bean-classpath-ManagedBean-class_org$jboss$seam$forge$shell$ShellImpl_$$WeldClientProxy.doShell(org$jboss$weld$bean-classpath-ManagedBean-class_org$jboss$seam$forge$shell$ShellImpl$$_WeldClientProxy.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.weld.util.reflection.SecureReflections$13.work(SecureReflections.java:305)
at org.jboss.weld.util.reflection.SecureReflectionAccess.run(SecureReflectionAccess.java:54)
at org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInvocation(SecureReflectionAccess.java:163)
at org.jboss.weld.util.reflection.SecureReflections.invoke(SecureReflections.java:299)
at org.jboss.weld.introspector.jlr.WeldMethodImpl.invokeOnInstance(WeldMethodImpl.java:188)
at org.jboss.weld.introspector.ForwardingWeldMethod.invokeOnInstance(ForwardingWeldMethod.java:59)
at org.jboss.weld.injection.MethodInjectionPoint.invokeOnInstanceWithSpecialValue(MethodInjectionPoint.java:198)
at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:270)
at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:253)
at org.jboss.weld.event.ObserverMethodImpl.notify(ObserverMethodImpl.java:222)
at org.jboss.weld.manager.BeanManagerImpl.notifyObservers(BeanManagerImpl.java:632)
at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:619)
at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:613)
at org.jboss.seam.forge.shell.Bootstrap$2.run(Bootstrap.java:92)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.seam.forge.shell.command.Execution.perform(Execution.java:139)
... 30 more
Caused by: org.eclipse.jgit.errors.TransportException: Could not delete file /tmp/forgetemp4740532537388554878/repo/.git/objects/incoming_7012870980931945616.idx
at org.eclipse.jgit.transport.BasePackFetchConnection.doFetch(BasePackFetchConnection.java:286)
at org.eclipse.jgit.transport.BasePackFetchConnection.fetch(BasePackFetchConnection.java:224)
at org.eclipse.jgit.transport.FetchProcess.fetchObjects(FetchProcess.java:214)
at org.eclipse.jgit.transport.FetchProcess.executeImp(FetchProcess.java:149)
at org.eclipse.jgit.transport.FetchProcess.execute(FetchProcess.java:111)
at org.eclipse.jgit.transport.Transport.fetch(Transport.java:904)
at org.jboss.seam.forge.git.Clone.runFetch(Clone.java:130)
at org.jboss.seam.forge.git.Clone.run(Clone.java:99)
at org.jboss.seam.forge.git.GitUtils.clone(GitUti