An error occurred while creating the staging directory for the feed: '[Details]'.
When building a feed, Package Builder first copies the packages and metadata files to a staging directory. An error occurred creating this staging directory. The directory path is too long, you do not have the correct permissions to create a directory at the path, or the drive or network location cannot be accessed.
Check that a directory can be created at the specified path and that you launch Package Builder with the correct user privileges.