watch_out_for_spill

New method which uses RubyCocoa with the FSEvents API from Rucola to watch if
files aren't installed outside the Homebrew prefix. Right now the paths being
watched are: /System, /usr, /etc, /sbin, /bin, and /Applications.

Library/Homebrew/beer_events.rb

@@ -0,0 +1,181 @@
+# Vendored from Rucola: http://github.com/alloy/rucola/tree/master
+#
+# Copyright (c) 2007, 2008, 2009 Eloy Duran <eloy.de.enige@gmail.com>
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation
+# files (the "Software"), to deal in the Software without
+# restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following
+# conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+
+require 'osx/cocoa'
+
+OSX.require_framework '/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework'
+
+module Rucola
+  class FSEvents
+    class FSEvent
+      attr_reader :fsevents_object
+      attr_reader :id
+      attr_reader :path
+      def initialize(fsevents_object, id, path)
+        @fsevents_object, @id, @path = fsevents_object, id, path
+      end
+      
+      # Returns an array of the files/dirs in the path that the event occurred in.
+      # The files are sorted by the modification time, the first entry is the last modified file.
+      def files
+        Dir.glob("#{File.expand_path(path)}/*").sort_by {|f| File.mtime(f) }.reverse
+      end
+      
+      # Returns the last modified file in the path that the event occurred in.
+      def last_modified_file
+        files.first
+      end
+    end
+    
+    class StreamError < StandardError; end
+    
+    attr_reader :paths
+    attr_reader :stream
+    
+    attr_accessor :allocator
+    attr_accessor :context
+    attr_accessor :since
+    attr_accessor :latency
+    attr_accessor :flags
+    
+    # Initializes a new FSEvents `watchdog` object and starts watching the directories you specify for events. The
+    # block is used as a handler for events, which are passed as the block's argument. This method is the easiest
+    # way to start watching some directories if you don't care about the details of setting up the event stream.
+    #
+    #   Rucola::FSEvents.start_watching('/tmp') do |events|
+    #     events.each { |event| log.debug("#{event.files.inspect} were changed.") }
+    #   end
+    #   
+    #   Rucola::FSEvents.start_watching('/var/log/system.log', '/var/log/secure.log', :since => last_id, :latency => 5) do
+    #     Growl.notify("Something was added to your log files!")
+    #   end
+    #
+    # Note that the method also returns the FSEvents object. This enables you to control the event stream if you want to.
+    #
+    #   fsevents = Rucola::FSEvents.start_watching('/Volumes') do |events|
+    #     events.each { |event| Growl.notify("Volume changes: #{event.files.to_sentence}") }
+    #   end
+    #   fsevents.stop
+    def self.start_watching(*params, &block)
+      fsevents = new(*params, &block)
+      fsevents.create_stream
+      fsevents.start
+      fsevents
+    end
+    
+    # Creates a new FSEvents `watchdog` object. You can specify a list of paths to watch and options to control the
+    # behaviour of the watchdog. The block you pass serves as a callback when an event is generated on one of the
+    # specified paths.
+    #
+    #   fsevents = FSEvents.new('/etc/passwd') { Mailer.send_mail("Someone touched the password file!") }
+    #   fsevents.create_stream
+    #   fsevents.start
+    #
+    #   fsevents = FSEvents.new('/home/upload', :since => UploadWatcher.last_event_id) do |events|
+    #     events.each do |event|
+    #       UploadWatcher.last_event_id = event.id
+    #       event.files.each do |file|
+    #         UploadWatcher.logfile.append("#{file} was changed")
+    #       end
+    #     end
+    #   end
+    #
+    # *:since: The service will report events that have happened after the supplied event ID. Never use 0 because that 
+    #   will cause every fsevent since the "beginning of time" to be reported. Use OSX::KFSEventStreamEventIdSinceNow
+    #   if you want to receive events that have happened after this call. (Default: OSX::KFSEventStreamEventIdSinceNow).
+    #   You can find the ID's passed with :since in the events passed to your block.
+    # *:latency: Number of seconds to wait until an FSEvent is reported, this allows the service to bundle events. (Default: 0.0)
+    #
+    # Please refer to the Cocoa documentation for the rest of the options.
+    def initialize(*params, &block)
+      raise ArgumentError, 'No callback block was specified.' unless block_given?
+      
+      options = params.last.kind_of?(Hash) ? params.pop : {}
+      @paths = params.flatten
+      
+      paths.each { |path| raise ArgumentError, "The specified path (#{path}) does not exist." unless File.exist?(path) }
+      
+      @allocator = options[:allocator] || OSX::KCFAllocatorDefault
+      @context   = options[:context]   || nil
+      @since     = options[:since]     || OSX::KFSEventStreamEventIdSinceNow
+      @latency   = options[:latency]   || 0.0
+      @flags     = options[:flags]     || 0
+      @stream    = options[:stream]    || nil
+      
+      @user_callback = block
+      @callback = Proc.new do |stream, client_callback_info, number_of_events, paths_pointer, event_flags, event_ids|
+        paths_pointer.regard_as('*')
+        events = []
+        number_of_events.times {|i| events << Rucola::FSEvents::FSEvent.new(self, event_ids[i], paths_pointer[i]) }
+        @user_callback.call(events)
+      end
+    end
+    
+    # Create the stream.
+    # Raises a Rucola::FSEvents::StreamError if the stream could not be created.
+    def create_stream
+      @stream = OSX.FSEventStreamCreate(@allocator, @callback, @context, @paths, @since, @latency, @flags)
+      raise(StreamError, 'Unable to create FSEvents stream.') unless @stream
+      OSX.FSEventStreamScheduleWithRunLoop(@stream, OSX.CFRunLoopGetCurrent, OSX::KCFRunLoopDefaultMode)
+    end
+    
+    # Start the stream.
+    # Raises a Rucola::FSEvents::StreamError if the stream could not be started.
+    def start
+      raise(StreamError, 'Unable to start FSEvents stream.') unless OSX.FSEventStreamStart(@stream)
+    end
+    
+    # Stop the stream.
+    # You can resume it by calling `start` again.
+    def stop
+      OSX.FSEventStreamStop(@stream)
+    end
+  end
+end
+
+# The complete BeerEvents API :)
+HOMEBREW_KEEP_DRY = %w{ /System /usr /etc /sbin /bin /Applications }
+
+def watch_out_for_spill
+  # Disable the RubyCocoa thread hook as apparently Laurent did not apply the
+  # thread patches to the OS X system Ruby
+  ENV['RUBYCOCOA_THREAD_HOOK_DISABLE'] = 'kampai'
+
+  Thread.new { OSX.CFRunLoopRun() }
+
+  start = Time.now
+  dog = Rucola::FSEvents.start_watching(*HOMEBREW_KEEP_DRY) do |events|
+    spill = events.map { |e| e.files }.flatten
+    spill.reject! { |f| File.mtime(f) < start }
+    spill.reject! { |path| path =~ /^#{HOMEBREW_PREFIX}/ }
+    unless spill.empty?
+      opoo "Detected installation of files outside the Homebrew prefix:"
+      puts *spill
+    end
+  end
+  yield
+ensure
+  dog.stop
+end

Library/Homebrew/utils.rb

@@ -34,7 +34,7 @@ end
 
 # shows a warning in delicious pink
 def opoo warning
-  puts "\033[1;35m==>\033[0;0;1m Warning\033[0;0m: #{warning}"
+  puts "\033[1;35m==>\033[0;0;1m Warning!\033[0;0m #{warning}"
 end
 
 def onoe error

bin/brew

@@ -93,9 +93,22 @@ begin
         raise "We cannot find a c compiler, have you installed the latest Xcode?"
       end
 
+      require 'beer_events'
+      
+      watch_out_for_spill do
+        ARGV.formulae.each do |f|
+          if f.installed? and not ARGV.force?
+            message = "Formula already installed: #{f.prefix}"
+            if ARGV.formulae.count > 1
+              opoo message
+            else
+              puts message # if only one is being installed a warning looks severe
+            end
+            next
+          end
+
           # we need to ensure a pristine ENV for each process or the formula
           # will start with the ENV from the previous build
-      ARGV.formulae.each do |f|
           pid=fork
           if pid.nil?
             exec __FILE__, "install-just-one", f.name, *ARGV.options
@@ -105,23 +118,35 @@ begin
           #FIXME I don't think $? represents the exit code from the child fork…
           exit! $? if $? != 0 # exception in other brew will be visible on screen
         end
+      end
 
     # this is an internal option, don't expose it to the user
     when 'install-just-one'
       require 'keg'
+
       f=ARGV.formulae.shift
-      raise "#{f.name} is already installed" if f.installed? unless ARGV.force?
+
       begin
         build_time=install f
         ohai "Caveats", f.caveats, ''
-        ohai 'Finishing up'
+        ohai 'Finishing up' if ARGV.verbose?
         clean f
         raise "Nothing was installed to #{f.prefix}" unless f.installed?
-        Keg.new(f.prefix).link
       rescue Exception
         f.prefix.rmtree if f.prefix.directory?
         raise
       end
+
+      begin
+        Keg.new(f.prefix).link
+      rescue Exception
+        onoe "The linking step did not complete successfully"
+        puts "The package built, but is not symlinked into #{HOMEBREW_PREFIX}"
+        puts "You can try again using `brew link #{f.name}'"
+        ohai "Summary" unless ARGV.verbose?
+      end
+
+      ohai "Summary" if ARGV.verbose?
       print "#{f.prefix}: #{f.prefix.abv}"
       print ", built in #{pretty_duration build_time}" if build_time
       puts
@@ -143,7 +168,10 @@ begin
       prune
 
     when 'up', 'update'
-      puts "Reserved command"
+      puts "You can't yet update :( But you can try:"
+      puts "    git pull"
+      puts "    brew rm foo"
+      puts "    brew install foo"
 
     when 'prune'
       prune