Doctor check for unlicensed Xcode

Checking the license text is probably the most future proofed method. Though for future reference other possible methods are listed in the below ticket.

Closes #14558.

2 files changed, 15 insertions, 2 deletions

diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index 0786d7c99..39fed18d9 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -925,6 +925,16 @@ def check_os_version
   end
 end
 
+  def check_xcode_license_approved
+    # If the user installs Xcode-only, they have to approve the
+    # license or no "xc*" tool will work.
+    <<-EOS.undent if `/usr/bin/xcrun clang 2>&1` =~ /license/ and not $?.success?
+    You have not agreed to the Xcode license.
+    Builds will fail! Agree to the license by opening Xcode.app or running:
+        xcodebuild -license
+    EOS
+  end
+
 end # end class Checks
 
 module Homebrew extend self
diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 85b502d1d..b01866958 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -37,8 +37,11 @@ module Homebrew extend self
 
   def check_xcode
     require 'cmd/doctor'
-    xcode = Checks.new.check_for_latest_xcode
-    opoo xcode unless xcode.nil?
+    checks = Checks.new
+    %w{check_for_latest_xcode check_xcode_license_approved}.each do |check|
+      out = checks.send(check)
+      opoo out unless out.nil?
+    end
   end
 
   def check_macports