Fix doctor's use of missing.

`brew doctor` shelled to `brew missing` and parsed the results.
When VERBOSE was true, this caused an error as extra, unexpected
output is generated.

Make missing an internal command, and give it a programmatic interface.

Library/Contributions/cmds/brew-missing.rb

-require "formula"
-require "cmd/outdated"
-
-def installed_brews
-  formulae = []
-  HOMEBREW_CELLAR.subdirs.each do |rack|
-    f = Formula.factory rack.basename.to_s rescue nil
-    formulae << f if f and f.installed?
-  end
-  formulae
-end
-
-def main
-  return unless HOMEBREW_CELLAR.exist?
-
-  # Names of outdated brews; they count as installed.
-  outdated = Homebrew.outdated_brews.collect{ |b| b.name }
-
-  formulae_to_check = if ARGV.named.empty?
-    installed_brews
-  else
-    ARGV.formulae
-  end
-
-  formulae_to_check.each do |f|
-    missing_deps = f.recursive_deps.map{ |g| g.name }.uniq.reject do |dep_name|
-      Formula.factory(dep_name).installed? or outdated.include?(dep_name)
-    end
-
-    unless missing_deps.empty?
-      print "#{f.name}: " if formulae_to_check.size > 1
-      puts "#{missing_deps * ' '}"
-    end
-  end
-end
-
-main()

Library/Homebrew/cmd/doctor.rb

+require 'set'
+require 'cmd/missing'
+
 class Volumes
   def initialize
     @volumes = []
@@ -752,18 +755,17 @@ def check_tmpdir
 end
 
 def check_missing_deps
-  s = []
-  `brew missing`.each_line do |line|
-    line =~ /(.*): (.*)/
-    $2.split.each do |dep|
-        s << dep unless s.include? dep
-    end
+  s = Set.new
+  missing_deps = Homebrew.find_missing_brews(Homebrew.installed_brews)
+  missing_deps.each do |m|
+    s.merge m[1]
   end
+
   if s.length > 0 then <<-EOS.undent
     Some installed formula are missing dependencies.
     You should `brew install` the missing dependencies:
 
-        brew install #{s * " "}
+        brew install #{s.to_a.sort * " "}
 
     Run `brew missing` for more details.
     EOS

Library/Homebrew/cmd/missing.rb

+require 'formula'
+require 'cmd/outdated'
+
+module Homebrew extend self
+  def installed_brews
+    formulae = []
+    HOMEBREW_CELLAR.subdirs.each do |rack|
+      f = Formula.factory rack.basename.to_s rescue nil
+      formulae << f if f and f.installed?
+    end
+    formulae
+  end
+
+  def find_missing_brews top_level
+    # Names of outdated brews; they count as installed.
+    outdated = Homebrew.outdated_brews.collect{ |b| b.name }
+
+    brews = []
+    top_level.each do |f|
+      missing_deps = f.recursive_deps.map{ |g| g.name }.uniq.reject do |dep_name|
+        Formula.factory(dep_name).installed? or outdated.include?(dep_name)
+      end
+
+      unless missing_deps.empty?
+        brews << [f.name, missing_deps]
+      end
+    end
+    brews
+  end
+
+  def missing
+    return unless HOMEBREW_CELLAR.exist?
+
+    formulae_to_check = if ARGV.named.empty?
+      installed_brews
+    else
+      ARGV.formulae
+    end
+
+    missing_deps = find_missing_brews(formulae_to_check)
+    missing_deps.each do |d|
+      name = d[0]
+      missing = d[1]
+      print "#{name}: " if formulae_to_check.size > 1
+      puts "#{missing * ' '}"
+    end
+  end
+end