--- configure.orig 2017-11-17 16:05:28.000000000 -0700 +++ configure 2018-04-25 08:15:04.000000000 -0700 @@ -22447,7 +22447,7 @@ fi -for ac_header in limits.h unistd.h ucontext.h +for ac_header in limits.h unistd.h do : as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh` ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"