Failed pgbench: setrandom invalid maximum number 0

Seeing the following on an old box I use for testing various
things. Thought it was something to do with my box at first,
but the problem seems to only occur in >= 8.4. But it's also
not pgbench alone, as it was working fine one day, and not the
next. Here's what I now get on 8.4, 9.0, and 9.1:

$ pgbench btest1 -n

setrandom: invalid maximum number 0
Client 0 aborted in state 3. Execution meta-command failed.
transaction type: TPC-B (sort of)
scaling factor: 0
query mode: simple
number of clients: 1
number of threads: 1
number of transactions per client: 10
number of transactions actually processed: 0/10
tps = 0.000000 (including connections establishing)
tps = 0.000000 (excluding connections establishing)

What I get on 8.3 and older is this:

$ pgbench btest1 -n

transaction type: TPC-B (sort of)
scaling factor: 1
number of clients: 1
number of transactions per client: 10
number of transactions actually processed: 10/10
tps = 332.005312 (including connections establishing)
tps = 372.703216 (excluding connections establishing)

Here's a snippet of strace for the failing run:

<<closing .pgpass>>
munmap(0xb773b000, 4096) = 0
socket(PF_FILE, SOCK_STREAM, 0) = 3
fcntl64(3, F_SETFL, O_RDONLY|O_NONBLOCK) = 0
fcntl64(3, F_SETFD, FD_CLOEXEC) = 0
connect(3, {sa_family=AF_FILE, path="/tmp/.s.PGSQL.5900"}, 110) = 0
getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
getsockname(3, {sa_family=AF_FILE, NULL}, [2]) = 0
time(NULL) = 1306638084
time(NULL) = 1306638084
poll([{fd=3, events=POLLOUT|POLLERR}], 1, 10000) = 1 ([{fd=3, revents=POLLOUT}])
send(3, "\0\0\0#\0\3\0\0user\0greg\0database\0btest"..., 35, MSG_NOSIGNAL) = 35
time(NULL) = 1306638084
poll([{fd=3, events=POLLIN|POLLERR}], 1, 10000) = 1 ([{fd=3, revents=POLLIN}])
recv(3, "R\0\0\0\10\0\0\0\0S\0\0\0\26application_name\0\0"..., 16384, 0) = 332
gettimeofday({1306638084, 217401}, NULL) = 0
write(2, "setrandom: invalid maximum numbe"..., 36setrandom: invalid maximum number 0
) = 36
write(2, "Client 0 aborted in state 3. Exe"..., 60Client 0 aborted in state 3. Execution meta-command failed.
) = 60
<<writing all the other lines seen above>>

--
Greg Sabino Mullane greg(at)endpoint(dot)com
End Point Corporation
PGP Key: 0x14964AC8