Executing a new modex is a little bit extreme. We can solve this by an approach
similar to what we use for connect/accept.
Step 1. the two leaders of the groups prepare a buffer with all the modex
information they have about their own group peers (if they don't have it they
can do a gather).
S
This problem resurfaced on the user list, so I dug around a bit and think I've
figured it out using George's test code. The problem lies in the fact that the
intercomm "merge" function can create a linkage between procs that was not
reflected anywhere in a modex, and so at least some of the proc
