audit: check for install options being shadowed

Library/Homebrew/cmd/audit.rb

@@ -125,16 +125,31 @@ def audit_formula_text name, text
   return problems
 end
 
+INSTALL_OPTIONS = %W[
+  --build-from-source
+  --debug
+  --devel
+  --force
+  --fresh
+  --HEAD
+  --ignore-dependencies
+  --interactive
+  --use-clang
+  --use-gcc
+  --use-llvm
+  --verbose
+].freeze
+
 def audit_formula_options f, text
   problems = []
 
-  # Find possible options
+  # Textually find options checked for in the formula
   options = []
   text.scan(/ARGV\.include\?[ ]*\(?(['"])(.+?)\1/) { |m| options << m[1] }
   options.reject! {|o| o.include? "#"}
-  options.uniq!
+  options.uniq! # May be checked more than once
 
-  # Find documented options
+  # Find declared options
   begin
     opts = f.options
     documented_options = []
@@ -156,6 +171,9 @@ def audit_formula_options f, text
       next if o == '--universal' and text =~ /ARGV\.build_universal\?/
       next if o == '--32-bit' and text =~ /ARGV\.build_32_bit\?/
       problems << " * Option #{o} is unused" unless options.include? o
+      if INSTALL_OPTIONS.include? o
+        problems << " * Option #{o} shadows an install option; should be renamed"
+      end
     end
   end