From 73ba9b3d880ae72e2dd8649d60b3a338ba744ac0 Mon Sep 17 00:00:00 2001
From: Shaun Jackman <sjackman@gmail.com>
Date: Tue, 20 Feb 2018 11:13:13 -0800
Subject: [PATCH] Define OS::Mac on Linux

Define MacOS.version, MacOS.full_version, and MacOS::Xcode.version to
Version::NULL on Linux so that brew readall succeeds and Homebrew/brew
can tap Homebrew/core on Linux.
---
 Library/Homebrew/os.rb       |  1 +
 Library/Homebrew/os/linux.rb | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 Library/Homebrew/os/linux.rb

diff --git a/Library/Homebrew/os.rb b/Library/Homebrew/os.rb
index d35a49dd7b..d56b032286 100644
--- a/Library/Homebrew/os.rb
+++ b/Library/Homebrew/os.rb
@@ -21,6 +21,7 @@ module OS
     end
     PATH_OPEN = "/usr/bin/open".freeze
   elsif OS.linux?
+    require "os/linux"
     ISSUES_URL = "https://github.com/Linuxbrew/brew/wiki/troubleshooting".freeze
     PATH_OPEN = "xdg-open".freeze
   end
diff --git a/Library/Homebrew/os/linux.rb b/Library/Homebrew/os/linux.rb
new file mode 100644
index 0000000000..e5af301b2f
--- /dev/null
+++ b/Library/Homebrew/os/linux.rb
@@ -0,0 +1,28 @@
+module OS
+  # Define OS::Mac on Linux for formula API compatibility.
+  module Mac
+    module_function
+
+    ::MacOS = self # rubocop:disable Naming/ConstantName
+
+    def prefer_64_bit?
+      Hardware::CPU.is_64_bit?
+    end
+
+    def version
+      Version::NULL
+    end
+
+    def full_version
+      Version::NULL
+    end
+
+    module Xcode
+      module_function
+
+      def version
+        Version::NULL
+      end
+    end
+  end
+end