Build: failed to generate the executable file

[pandax381]

$ make
...
Scanning dependencies of target fluent-bit-bin
[ 81%] Building C object src/CMakeFiles/fluent-bit-bin.dir/fluent-bit.c.o
Linking C executable ../bin/fluent-bit
../library/libmk_core.a(mk_event.c.o): In function `mk_utils_libc_error':
mk_event.c:(.text+0x81): undefined reference to `pthread_getspecific'
collect2: error: ld returned 1 exit status
make[2]: *** [bin/fluent-bit] Error 1
make[1]: *** [src/CMakeFiles/fluent-bit-bin.dir/all] Error 2
make: *** [all] Error 2