From fe8f3c4b13ee49f44565ed88380e70781499f193 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Tue, 22 Dec 2020 08:41:49 +0000
Subject: [PATCH] install: clarify "on Intel" error if under Rosetta 2.

Inspired by https://github.com/Homebrew/brew/issues/10088
---
 Library/Homebrew/install.rb | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/install.rb b/Library/Homebrew/install.rb
index 155a480996..abb931c980 100644
--- a/Library/Homebrew/install.rb
+++ b/Library/Homebrew/install.rb
@@ -30,8 +30,14 @@ module Homebrew
     end
 
     def check_prefix
-      if Hardware::CPU.intel? && HOMEBREW_PREFIX.to_s == HOMEBREW_MACOS_ARM_DEFAULT_PREFIX
-        odie "Cannot install in Homebrew on Intel processor in ARM default prefix (#{HOMEBREW_PREFIX})!"
+      if (Hardware::CPU.intel? || Hardware::CPU.in_rosetta2?) &&
+         HOMEBREW_PREFIX.to_s == HOMEBREW_MACOS_ARM_DEFAULT_PREFIX
+        configuration = if Hardware::CPU.in_rosetta2?
+          "on Intel processor"
+        else
+          "under Rosetta 2"
+        end
+        odie "Cannot install in Homebrew #{configuration} in ARM default prefix (#{HOMEBREW_PREFIX})!"
       elsif Hardware::CPU.arm? && HOMEBREW_PREFIX.to_s == HOMEBREW_DEFAULT_PREFIX
         odie <<~EOS
           Cannot install in Homebrew on ARM processor in Intel default prefix (#{HOMEBREW_PREFIX})!