comment about our twisted patch

nixos/pkgs/twisted.nix

 { twisted }:
 twisted.overrideAttrs (old: {
-  version = old.version + "-0";
   prePatch = old.patchPhase;
   patchPhase = null;
+  # Add a patch which adds more logging to a namer resolver failure case.  The
+  # NixOS system test harness might be setting up a weird semi-broken system
+  # that provokes a weird behavior out of getaddrinfo() that Twisted doesn't
+  # normally handle.  The logging can help with debugging this case.  We
+  # should think about upstreaming something related to this.
   patches = (if old ? "patches" then old.patches else []) ++ [ ./twisted.patch ];
 })