[go-nuts] Significance of using a buffered channel of capacity 1.

... that's the point. If the channel is a "done" channel, it's there only
to signal when the taks it's done, there's no value to process (that's why
I would use a chan of struct{}).
So when you want to wait for the task to be completed, you do:
<-done
And that blocks until the channel gets closed (when the job is done). And
you get nothing (an empty struct) out of the channel, because there's no
data to process.
(hope I didn't misunderstand your question)