It says on several places in the Perforce documentation that it is possible to convert a task stream to a development stream, but I did not find how to actually do it.
In P4V, when I right-click a stream in the Stream view and choose Edit stream 'X', there's the Stream type combobox where I think I am supposed to change the 'task' option to 'development'. For development streams, I can use the combobox to convert the stream to for example a mainline or virtual stream, but for all my tasks streams, the combobox is disabled.
How can I convert the task stream to a development stream? Is there some prerequisite condition that I have to fulfill?