From 8e6731b7c72180edfa090d5752f1a9bb385aa511 Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Fri, 23 Jul 2021 11:40:01 +0800
Subject: [PATCH] formula_cellar_checks: show mismatched arch in
 `check_binary_arches`

This will make the error more informative by showing the architecture a
binary was built for along with the error message.

Before:

    foo:
      * Binaries built for an incompatible architecture were installed into foo's prefix.
        The offending files are:
          /usr/local/Cellar/foo/1.0/lib/libbar.dylib
          /usr/local/Cellar/foo/1.0/lib/libfoo.dylib
          /usr/local/Cellar/foo/1.0/lib/libincompatible.dylib
        Unexpected universal binaries were found.
        The offending files are:
          /usr/local/Cellar/foo/1.0/lib/liball.dylib
          /usr/local/Cellar/foo/1.0/lib/libuniversal.dylib

After:

    foo:
      * Binaries built for a non-native architecture were installed into foo's prefix.
        The offending files are:
          /usr/local/Cellar/foo/1.0/lib/libbar.dylib        (i386)
          /usr/local/Cellar/foo/1.0/lib/libfoo.dylib        (arm64)
          /usr/local/Cellar/foo/1.0/lib/libincompatible.dylib       (universal)
        Unexpected universal binaries were found.
        The offending files are:
          /usr/local/Cellar/foo/1.0/lib/liball.dylib
          /usr/local/Cellar/foo/1.0/lib/libuniversal.dylib
---
 Library/Homebrew/formula_cellar_checks.rb | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/Library/Homebrew/formula_cellar_checks.rb b/Library/Homebrew/formula_cellar_checks.rb
index dde65b9769..1ba4a41a7e 100644
--- a/Library/Homebrew/formula_cellar_checks.rb
+++ b/Library/Homebrew/formula_cellar_checks.rb
@@ -320,14 +320,16 @@ module FormulaCellarChecks
     return if !OS.mac? && !OS.linux?
 
     keg = Keg.new(formula.prefix)
-    mismatches = keg.binary_executable_or_library_files.reject do |file|
-      file.arch == Hardware::CPU.arch
+    mismatches = {}
+    keg.binary_executable_or_library_files.each do |file|
+      farch = file.arch
+      mismatches[file] = farch unless farch == Hardware::CPU.arch
     end
     return if mismatches.empty?
 
-    compatible_universal_binaries, mismatches = mismatches.partition do |file|
-      file.arch == :universal && file.archs.include?(Hardware::CPU.arch)
-    end
+    compatible_universal_binaries, mismatches = mismatches.partition do |file, arch|
+      arch == :universal && file.archs.include?(Hardware::CPU.arch)
+    end.map(&:to_h) # To prevent transformation into nested arrays
 
     universal_binaries_expected = if formula.tap.present? && formula.tap.core_tap?
       tap_audit_exception(:universal_binary_allowlist, formula.name)
@@ -340,9 +342,9 @@ module FormulaCellarChecks
 
     if mismatches.present?
       s += <<~EOS
-        Binaries built for an incompatible architecture were installed into #{formula}'s prefix.
+        Binaries built for a non-native architecture were installed into #{formula}'s prefix.
         The offending files are:
-          #{mismatches * "\n  "}
+          #{mismatches.map { |m| "#{m.first}\t(#{m.last})" } * "\n  "}
       EOS
     end
 
@@ -350,7 +352,7 @@ module FormulaCellarChecks
       s += <<~EOS
         Unexpected universal binaries were found.
         The offending files are:
-          #{compatible_universal_binaries * "\n  "}
+          #{compatible_universal_binaries.keys * "\n  "}
       EOS
     end