compiler construction - undefined reference to ruserok error -

i've run strange "undefined reference to" compile error cannot seem find resolution for. i'm trying configure/compile pam 1.1.6 gumstix overo using yocto project generated arm compiler (arm-poky-linux-gnueabi-gcc), keep getting following error during compilation:

.libs/pam_rhosts.o: in function `pam_sm_authenticate': modules/pam_rhosts/pam_rhosts.c:117: undefined reference `ruserok' collect2: error: ld returned 1 exit status 

so, did investigating , found out during configure, following test code compiled , executed determine availability of ruserok, ruserok_af , iruserok.

/* end confdefs.h.  */ /* define $2 innocuous variant, in case <limits.h> declares $2.    example, hp-ux 11i <limits.h> declares gettimeofday.  */ #define $2 innocuous_$2  /* system header define __stub macros , few prototypes,     can conflict char $2 (); below.     prefer <limits.h> <assert.h> if __stdc__ defined, since     <limits.h> exists on freestanding compilers.  */  #ifdef __stdc__ # include <limits.h> #else # include <assert.h> #endif  #undef $2  /* override gcc internal prototype avoid error.    use char because int might match return type of gcc    builtin , argument prototype still apply.  */ #ifdef __cplusplus extern "c" #endif char $2 (); /* gnu c library defines functions implements     fail enosys.  functions named     starting __ , normal name alias.  */ #if defined __stub_$2 || defined __stub___$2 choke me #endif  int main () { return $2 ();   ;   return 0; } 

so, copied, pasted (replacing of $2's ruserok) , compiled code using generated gcc compiler

./arm-poky-linux-gnueabi-gcc -o test.o test.c 

to see if ruserok, ruserok_af , iuserok functions do/don't exist, , received following compilation error:

/tmp/ccu8yszi.o: in function `main': test.c:(.text+0x8): undefined reference `ruserok' collect2: error: ld returned 1 exit status 

which, same "undefined reference `ruserok'" error above. sanity check, since had installed ubuntu/linaro arm gcc compiler through ubuntu software center earlier, compiled same code arm-linux-gnueabi-gcc compiler, code compiled fine without errors. here command used reference:

arm-linux-gnueabi-gcc -o test.o test.c 

so, question is: why 1 compiler produce "undefined reference ruserok" error, while other not? or asked differently, difference between 2 compilers 1 compiler produce "undefined reference ruserok" error?

compilers (and in particular gcc) more code generators. intimately familiar libc, or standard c library , libgcc compiler helper library. general command lines implicitly use -lc (link libc). arm-linux-gnueabi-gcc ubuntu crosstool-ng build eglibc.

i have no idea poky gcc about. might provide link got compiler from. poky configuration link, seems compiler mult-lib distribution or , there additional steps need perform configure cross-build.

the answer question,

why 1 compiler produce "undefined reference ruserok" error, while other not?

because 1 has ruserok in library , other doesn't (or isn't configured see it).