This option allows you to specify a different target for debug output. All components have a default log file which will norally be in /tmp or /var/log and this is where debug will be written to if this value is empty. Adding a path here will temporarily redirect debug, and other logging output, to this file. This option is a simple filename and you are debugging several components then they will all try and write to the same file with undesirable consequences. Appending a '+' to the filename will cause the file to be created with a '.<pid>' suffix containing your process id. In this way debug from each run of a component is kept separate. This is the recommended setting as it will also prevent subsequent runs from overwriting the same log. You should ensure that permissions are set up to allow writing to the file and directory specified here.