-verbose makes purr-data dump core on Linux

I just noticed this while playing with the new startup configuration from !53 (merged) (but the same happens with current git, so it's not related to !53 (merged) in any way). To reproduce, run purr-data with -verbose. Here's what I get after the intial flurry of messages in the terminal:

watchdog: signaling pd...
watchdog: signaling pd...
recv: Interrupted system call (4)

gdb backtrace:

#0  0x00007ffff64790b3 in select () from /usr/lib/libc.so.6
#1  0x00000000004a2f5d in sys_domicrosleep (microsec=<optimized out>, pollem=1)
    at s_inter.c:201
#2  0x00000000004a3075 in sys_microsleep (microsec=<optimized out>)
    at s_inter.c:230
#3  0x00000000004a0196 in m_pollingscheduler () at m_sched.c:562
#4  m_mainloop () at m_sched.c:622
#5  0x00000000004a2a2b in sys_main (argc=<optimized out>, argv=<optimized out>)
    at s_main.c:344
#6  0x00007ffff63b8291 in __libc_start_main () from /usr/lib/libc.so.6
#7  0x0000000000417d2a in _start ()

This is on Arch (Manjaro) running the latest from git.