diff -up ./esc/src/xulrunner/xulrunner-mozconfig.fix2 ./esc/src/xulrunner/xulrunner-mozconfig
--- ./esc/src/xulrunner/xulrunner-mozconfig.fix2	2018-04-30 13:48:53.944086197 -0700
+++ ./esc/src/xulrunner/xulrunner-mozconfig	2018-04-30 13:49:22.804921349 -0700
@@ -37,6 +37,7 @@ ac_add_options --disable-skia
 ac_add_options --with-system-nspr
 ac_add_options --with-system-nss
 ac_add_options --disable-crashreporter
+ac_add_options --disable-startupcache
 
 export BUILD_OFFICIAL=1
 export MOZILLA_OFFICIAL=1