compiling 2.0.5 and make error

[mikeyao]

posix.c: In function 'scm_nice':
posix.c:1632:8: warning: ignoring return value of 'nice', 
declared with attribute warn_unused_result [-Wunused-result]
  CC     net_db.lo
  CC     socket.lo
  CC     regex-posix.lo
  CCLD   libguile-2.0.la
  CC     guile-guile.o
  CCLD   guile
./.libs/libguile-2.0.so: undefined reference to `GC_unregister_my_thread'
./.libs/libguile-2.0.so: undefined reference to `GC_pthread_create'
./.libs/libguile-2.0.so: undefined reference to `GC_register_my_thread'
./.libs/libguile-2.0.so: undefined reference to `GC_pthread_detach'
collect2: ld returned 1 exit status
make[3]: *** [guile] Error 1
make[3]: Leaving directory `/home/mikeyao/code/guile-2.0.5/libguile'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/home/mikeyao/code/guile-2.0.5/libguile'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/mikeyao/code/guile-2.0.5'
make: *** [all] Error 2