From adab0fbb41676410229228e96d81f7d5319c719a Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Wed, 9 Dec 2020 11:50:45 +0000
Subject: [PATCH] cleanup: fix portable Ruby behaviour.

Better match the macOS behaviour in `ruby.sh`.

Fixes #9469
---
 Library/Homebrew/brew.sh    | 1 +
 Library/Homebrew/cleanup.rb | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index d448ca3337..871c08ab93 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -455,6 +455,7 @@ export HOMEBREW_MACOS_VERSION_NUMERIC
 export HOMEBREW_USER_AGENT
 export HOMEBREW_USER_AGENT_CURL
 export HOMEBREW_BOTTLE_DEFAULT_DOMAIN
+export HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH
 
 if [[ -n "$HOMEBREW_MACOS" && -x "/usr/bin/xcode-select" ]]
 then
diff --git a/Library/Homebrew/cleanup.rb b/Library/Homebrew/cleanup.rb
index 2a8f57c92d..93730daced 100644
--- a/Library/Homebrew/cleanup.rb
+++ b/Library/Homebrew/cleanup.rb
@@ -361,6 +361,8 @@ module Homebrew
 
       use_system_ruby = if Homebrew::EnvConfig.force_vendor_ruby?
         false
+      elsif OS.mac?
+        ENV["HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH"].present?
       else
         check_ruby_version = HOMEBREW_LIBRARY_PATH/"utils/ruby_check_version_script.rb"
         rubies.uniq.any? do |ruby|