Segmenation fault in update_sdb

ltrace ./rabin2 ../radare2/CoST.exe 
__libc_start_main(0x402501, 2, 0x7fffa50c62b8, 0x403c90, 0x403c80 <unfinished ...>
r_str_home(0x404530, 0x7fffa50c62b8, 0x7fffa50c62d0, 0, 0x7f6211552320)                             = 0x1d85030
r_core_init(0x7fffa5064d70, 0, 0, 0, 0xfefefefefefefeff <unfinished ...>
--- SIGSEGV (Segmentation fault) ---
+++ killed by SIGSEGV +++