diff -u -r ../php-5.6.15/ext/opcache/config.m4 ./ext/opcache/config.m4
--- ../php-5.6.15/ext/opcache/config.m4	2015-10-29 05:55:01.000000000 -0400
+++ ./ext/opcache/config.m4	2015-11-10 15:24:37.080935147 -0500
@@ -341,7 +341,15 @@
 	flock_type=linux
     AC_DEFINE([HAVE_FLOCK_LINUX], [], [Struct flock is Linux-type])
     AC_MSG_RESULT("yes")
-], AC_MSG_RESULT("no") )
+], [
+    AC_MSG_RESULT("no")
+], [
+    dnl cross-compiling; assume Linux
+    flock_type=linux
+    AC_DEFINE([HAVE_FLOCK_LINUX], [], [Struct flock is Linux-type])
+    AC_MSG_RESULT("yes")
+])
+
 
 AC_MSG_CHECKING("whether flock struct is BSD ordered")
 AC_TRY_RUN([
@@ -357,7 +365,13 @@
 	flock_type=bsd
     AC_DEFINE([HAVE_FLOCK_BSD], [], [Struct flock is BSD-type]) 
     AC_MSG_RESULT("yes")
-], AC_MSG_RESULT("no") )
+], [
+    AC_MSG_RESULT("no")
+], [
+    dnl cross-compiling; assume Linux
+    AC_MSG_RESULT("no")
+])
+
 
 if test "$flock_type" == "unknown"; then
 	AC_MSG_ERROR([Don't know how to define struct flock on this system[,] set --enable-opcache=no])