System can no longer be reconfigured

[Development of GNU Guix and the GNU System distribution.]

Hi,

I can no longer reconfigure a system with any of these methods:

1. "guix deploy" which I use almost exclusively
2. "guix system reconfigure" after a recent pull
3. "./pre-inst-env guix system reconfigure" with a recent Git checkout.

Guix hangs during the system activation step.  Any ideas?

Kind regards
Felix