Comment 9 for bug 907675

Update: we finished upgrading Launchpad production to xenial earlier this year; I just landed the conversion of our build system to pip; and I have a branch in progress to upgrade us to Twisted 16.5.0.

The upstream Twisted work doesn't seem to have finished yet, so we may be near the point where we've done everything we can for the time being. Versions of Twisted newer than 16.5.0 remove gmpy integration, so we'll need to take some care to avoid regressing performance on new connections, but that's doable.