doc: add an installation issue on the FAQ page

FAQ.md

@@ -109,3 +109,54 @@ curl -i http://127.0.0.1:9080/apisix/admin/routes/2 -X PUT -d '
 
 Here is the operator list of current `lua-resty-radixtree`：
 https://github.com/iresty/lua-resty-radixtree#operator-list
+
+## How to fix OpenResty Installation Failure on MacOS 10.15
+When you install the OpenResty on MacOs 10.15, you may face this error
+```shell
+> brew install openresty
+Updating Homebrew...
+==> Auto-updated Homebrew!
+Updated 1 tap (homebrew/cask).
+No changes to formulae.
+
+==> Installing openresty from openresty/brew
+Warning: A newer Command Line Tools release is available.
+Update them from Software Update in System Preferences or
+https://developer.apple.com/download/more/.
+
+==> Downloading https://openresty.org/download/openresty-1.15.8.2.tar.gz
+Already downloaded: /Users/wusheng/Library/Caches/Homebrew/downloads/4395089f0fd423261d4f1124b7beb0f69e1121e59d399e89eaa6e25b641333bc--openresty-1.15.8.2.tar.gz
+==> ./configure -j8 --prefix=/usr/local/Cellar/openresty/1.15.8.2 --pid-path=/usr/local/var/run/openresty.pid --lock-path=/usr/
+Last 15 lines from /Users/wusheng/Library/Logs/Homebrew/openresty/01.configure:
+DYNASM    host/buildvm_arch.h
+HOSTCC    host/buildvm.o
+HOSTLINK  host/buildvm
+BUILDVM   lj_vm.S
+BUILDVM   lj_ffdef.h
+BUILDVM   lj_bcdef.h
+BUILDVM   lj_folddef.h
+BUILDVM   lj_recdef.h
+BUILDVM   lj_libdef.h
+BUILDVM   jit/vmdef.lua
+make[1]: *** [lj_folddef.h] Segmentation fault: 11
+make[1]: *** Deleting file `lj_folddef.h'
+make[1]: *** Waiting for unfinished jobs....
+make: *** [default] Error 2
+ERROR: failed to run command: gmake -j8 TARGET_STRIP=@: CCDEBUG=-g XCFLAGS='-msse4.2 -DLUAJIT_NUMMODE=2 -DLUAJIT_ENABLE_LUA52COMPAT' CC=cc PREFIX=/usr/local/Cellar/openresty/1.15.8.2/luajit
+
+If reporting this issue please do so at (not Homebrew/brew or Homebrew/core):
+  https://github.com/openresty/homebrew-brew/issues
+
+These open issues may also help:
+Can't install openresty on macOS 10.15 https://github.com/openresty/homebrew-brew/issues/10
+The openresty-debug package should use openresty-openssl-debug instead https://github.com/openresty/homebrew-brew/issues/3
+Fails to install OpenResty https://github.com/openresty/homebrew-brew/issues/5
+
+Error: A newer Command Line Tools release is available.
+Update them from Software Update in System Preferences or
+https://developer.apple.com/download/more/.
+```
+
+This is an OS incompatible issue, you could fix by these two steps
+1. `brew edit openresty/brew/openresty`
+1. add `\ -fno-stack-check` in with-luajit-xcflags line.