[CC] extconf.c -> extconf.o
   [LD] aelparse.o aelbison.o pbx_ael.o ael_main.o ast_expr2f.o ast_expr2.o strcompat.o pval.o extconf.o -> aelparse
Undefined                       first referenced
 symbol                             in file
ast_atomic_fetchadd_int_slow        extconf.o
ld: fatal: Symbol referencing errors. No output written to aelparse
collect2: ld returned 1 exit status
gmake[1]: *** [aelparse] Error 1
gmake: *** [utils] Error 2