Graphical install: after finishing with the disk druid screen the install hangs. ps aux reveals nothing of note, and no error messages on any console screens. Text install: On leaving the disk druid screen the install terminates with signal 11. This SEGV also happens if you use fdisk, when you choose "done".
I have traced this problem to a mangled partition table. I wrote zeros over it and started from scratch, everything works fine now.