Program received signal SIGSEGV, Segmentation fault.
ngx_http_fastcgi_process_header (r=0x1756220) at src/http/modules/ngx_http_fastcgi_module.c:1261
1261	            start = u->buffer.start + r->cache->header_start;
(gdb) bt 
#0  ngx_http_fastcgi_process_header (r=0x1756220) at src/http/modules/ngx_http_fastcgi_module.c:1261
#1  0x0000000000445f5a in ngx_http_upstream_process_header (r=0x1756220, u=0x17548b0) at src/http/ngx_http_upstream.c:1520
#2  0x000000000044306d in ngx_http_upstream_handler (ev=0x16cad60) at src/http/ngx_http_upstream.c:878
#3  0x00000000004242f4 in ngx_epoll_process_events (cycle=0x160c5f0, timer=<value optimized out>, 
    flags=<value optimized out>) at src/event/modules/ngx_epoll_module.c:642
#4  0x000000000041bcde in ngx_process_events_and_timers (cycle=0x160c5f0) at src/event/ngx_event.c:245
#5  0x0000000000422995 in ngx_worker_process_cycle (cycle=0x160c5f0, data=<value optimized out>)
    at src/os/unix/ngx_process_cycle.c:795
#6  0x0000000000420da4 in ngx_spawn_process (cycle=0x160c5f0, proc=<value optimized out>, data=<value optimized out>, 
    name=0x479606 "worker process", respawn=-3) at src/os/unix/ngx_process.c:196
#7  0x0000000000421dd2 in ngx_start_worker_processes (cycle=0x160c5f0, n=1, type=-3)
    at src/os/unix/ngx_process_cycle.c:355
#8  0x0000000000423124 in ngx_master_process_cycle (cycle=0x160c5f0) at src/os/unix/ngx_process_cycle.c:136
#9  0x0000000000406842 in main (argc=<value optimized out>, argv=<value optimized out>) at src/core/nginx.c:396