Yup, that's another flawed line. It seems like it's not possible to share generators between processes through Pool.map(). Apart from this, using the raw Pool.map won't let us distribute the workload over more than one machine if we need to. On the other hand, I'd suggest you to take a look at [this map_reader example](http://discoproject.org/doc/disco/start/tutorial_2.html#write-a-job-using-a-derived-class) in Disco. I'll try this out and see if it works.