qemu core dumps with -serial mon:vc

qemu 1.5.2-1 dumps core when asked to put the monitor on a virtual console.  For example, suppose you want to monitor the second serial port, you might try something like:

qemu-system-x86_64 -serial null -serial mon:vc

But that creates a core dump.  In fact, even re-creating what should be the default dumps core:

$ qemu-system-x86_64 -serial mon:vc:80Cx25C
Segmentation fault (core dumped)

I'm not including a backtrace because the bug is so easy to reproduce, but I can provide more info if necessary.