i've problem with the deployment of an grails app.

i get the following exception:

log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: stacktrace.log (Permission denied)
    at java.io.FileOutputStream.openAppend(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:177)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:102)
    at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
    at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
    at org.apache.log4j.spi.OptionHandler$activateOptions.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:40)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)
    at org.codehaus.groovy.grails.plugins.logging.Log4jConfig.createFullstackTraceAppender(Log4jConfig.groovy:177)
    at org.codehaus.groovy.grails.plugins.logging.Log4jConfig.this$2$createFullstackTraceAppender(Log4jConfig.groovy)
    at org.codehaus.groovy.grails.plugins.logging.Log4jConfig$this$2$createFullstackTraceAppender.callCurrent(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:44)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:145)
    at org.codehaus.groovy.grails.plugins.logging.Log4jConfig.configure(Log4jConfig.groovy:145)
    at org.codehaus.groovy.grails.web.util.Log4jConfigListener.contextInitialized(Log4jConfigListener.java:62)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4135)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4630)
    at org.apache.catalina.core.Container
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