Core was generated by `./bfgminer-43541e8a -c puppet.json -S icarus:/dev/ttyUSB1 -S icarus:/dev/ttyUSB'.
Program terminated with signal 11, Segmentation fault.
#0 0xf76e1714 in curl_easy_reset () from /usr/lib/libcurl.so.4
(gdb) bt
#0 0xf76e1714 in curl_easy_reset () from /usr/lib/libcurl.so.4
#1 0x0805deb7 in json_rpc_call (curl=0x0, url=0x80efce8 "http://api.bitcoin.cz:8332",
userpass=0x80fcc08 "luke-jr.FPGAs:x",
rpc_req=0x80d18e4 "{\"method\": \"getwork\", \"params\": [], \"id\":0}\r\n", probe=false, longpoll=false,
rolltime=0x81dc4a8, pool=0x80f0888, share=false) at util.c:449
#2 0x0804fbd0 in get_upstream_work (work=0x81dc360, curl=0x0) at miner.c:2111
#3 0x08050526 in get_work_thread (userdata=0xf0900740) at miner.c:2384
#4 0xf7719ed3 in start_thread () from /lib/libpthread.so.0
#5 0xf75823ee in clone () from /lib/libc.so.6