nagios-plugins segfault

ds412p> strace ./check_users -w 5
execve("./check_users", ["./check_users", "-w", "5"], [/* 18 vars */]) = 0
brk(0)                                  = 0x8051000
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xf77c1000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = -1 ENOENT (No such file or directory)
open("/lib/tls/i686/sse2/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/tls/i686/sse2", 0xfffdfee8) = -1 ENOENT (No such file or directory)
open("/lib/tls/i686/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/tls/i686", 0xfffdfee8)     = -1 ENOENT (No such file or directory)
open("/lib/tls/sse2/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/tls/sse2", 0xfffdfee8)     = -1 ENOENT (No such file or directory)
open("/lib/tls/libc.so.6", O_RDONLY)    = -1 ENOENT (No such file or directory)
stat64("/lib/tls", 0xfffdfee8)          = -1 ENOENT (No such file or directory)
open("/lib/i686/sse2/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/i686/sse2", 0xfffdfee8)    = -1 ENOENT (No such file or directory)
open("/lib/i686/libc.so.6", O_RDONLY)   = -1 ENOENT (No such file or directory)
stat64("/lib/i686", 0xfffdfee8)         = -1 ENOENT (No such file or directory)
open("/lib/sse2/libc.so.6", O_RDONLY)   = -1 ENOENT (No such file or directory)
stat64("/lib/sse2", 0xfffdfee8)         = -1 ENOENT (No such file or directory)
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0P\217\1\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0555, st_size=1528336, ...}) = 0
mmap2(NULL, 1538568, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xf7649000
mprotect(0xf77ba000, 4096, PROT_NONE)   = 0
mmap2(0xf77bb000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x171) = 0xf77bb000
mmap2(0xf77be000, 10760, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xf77be000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xf7648000
set_thread_area({entry_number:-1 -> 12, base_addr:0xf76486c0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xf77bb000, 8192, PROT_READ)   = 0
mprotect(0xf77e1000, 4096, PROT_READ)   = 0
brk(0)                                  = 0x8051000
brk(0x8072000)                          = 0x8072000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=13731024, ...}) = 0
mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0xf7448000
close(3)                                = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV (core dumped) +++
Segmentation fault (core dumped)