From 342f8e1e71d83d6a8a0e225964b90041f4367dc6 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Fri, 5 Nov 2021 12:35:46 +0000
Subject: [PATCH] vendor-install: better handle /usr/local arm64 ruby.

Fixes https://github.com/Homebrew/brew/issues/12351
---
 Library/Homebrew/cmd/vendor-install.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/cmd/vendor-install.sh b/Library/Homebrew/cmd/vendor-install.sh
index 7a13aea315..10ca3630f0 100644
--- a/Library/Homebrew/cmd/vendor-install.sh
+++ b/Library/Homebrew/cmd/vendor-install.sh
@@ -14,7 +14,11 @@ VENDOR_DIR="${HOMEBREW_LIBRARY}/Homebrew/vendor"
 # Built from https://github.com/Homebrew/homebrew-portable-ruby.
 if [[ -n "${HOMEBREW_MACOS}" ]]
 then
-  if [[ "${HOMEBREW_PROCESSOR}" == "Intel" ]]
+  if [[ "${HOMEBREW_PROCESSOR}" == "Intel" ]] ||
+     # Handle the case where /usr/local/bin/brew is run under arm64.
+     # It's a x86_64 installation there (we refuse to install arm64 binaries) so
+     # use a x86_64 Portable Ruby.
+     [[ "${HOMEBREW_PROCESSOR}" == "arm64" && "${HOMEBREW_PREFIX}" == "/usr/local" ]]
   then
     ruby_FILENAME="portable-ruby-2.6.8.yosemite.bottle.tar.gz"
     ruby_SHA="0cb1cc7af109437fe0e020c9f3b7b95c3c709b140bde9f991ad2c1433496dd42"