diff -u -r ../perl-5.22.0/cnf/configure_func.sh ./cnf/configure_func.sh
--- ../perl-5.22.0/cnf/configure_func.sh	2015-08-26 08:27:51.000000000 -0400
+++ ./cnf/configure_func.sh	2015-08-30 18:07:01.233675759 -0400
@@ -260,7 +260,8 @@
 check hasfunc shmdt
 check hasfunc shmget
 check hasfunc sigaction
-check hasfunc signbit '.0' 'math.h'
+# Avoid using signbit only available on build machine:
+# check hasfunc signbit '.0' 'math.h'
 check hasfunc sigprocmask
 check hasfunc sigsetjmp "NULL,0" 'stdlib.h setjmp.h'
 check hasfunc snprintf