diff -up 0ad-0.0.23b-alpha/libraries/source/spidermonkey/build.sh.orig 0ad-0.0.23b-alpha/libraries/source/spidermonkey/build.sh
--- 0ad-0.0.23b-alpha/libraries/source/spidermonkey/build.sh.orig	2019-09-30 15:33:27.690089303 -0300
+++ 0ad-0.0.23b-alpha/libraries/source/spidermonkey/build.sh	2019-09-30 15:47:16.201374941 -0300
@@ -27,7 +27,7 @@ fi
 
 MAKE_OPTS="${JOBS}"
 
-CONF_OPTS="--enable-shared-js --disable-tests --without-intl-api"
+CONF_OPTS="--enable-shared-js --disable-tests --without-intl-api --disable-optimize"
 
 # Bug 1269319
 # When compiled with GCC 6 (or later), SpiderMonkey 38 (and versions up to 49) is
@@ -37,7 +37,7 @@ if [ "${OS}" != "Windows_NT" ]
 then
   if [ "`${CXX:=g++} -dumpversion | cut -f1 -d.`" -ge "6" ]
   then
-    CXXFLAGS="${CXXFLAGS} -fno-schedule-insns2 -fno-delete-null-pointer-checks"
+    CXXFLAGS="${CXXFLAGS} -fpermissive -fno-tree-vrp -fno-strict-aliasing -fno-schedule-insns2 -fno-delete-null-pointer-checks"
   fi
 fi