[Executable] fix NameError

CHANGELOG.md

@@ -20,6 +20,9 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
   [Juan Civile](https://github.com/champo)
   [#5282](https://github.com/CocoaPods/CocoaPods/issues/5282)
 
+* Fix error when executables cannot be found.
+  [Jan Berkel](https://github.com/jberkel)
+  [#5319](https://github.com/CocoaPods/CocoaPods/pull/5319)
 
 ## 1.0.0 (2016-05-10)
 

lib/cocoapods/executable.rb

@@ -108,7 +108,7 @@ module Pod
     #
     def self.which!(program)
       which(program).tap do |bin|
-        raise Informative, "Unable to locate the executable `#{executable}`" unless bin
+        raise Informative, "Unable to locate the executable `#{program}`" unless bin
       end
     end
 

spec/unit/executable_spec.rb

@@ -73,6 +73,13 @@ module Pod
       io.should == " 0\n 1\n 2\n"
     end
 
+    it 'shows the name in the error message when the command was not found' do
+      e = lambda do
+        Executable.execute_command('___notfound___', [], true)
+      end.should.raise Informative
+      e.message.should.match /___notfound___/
+    end
+
     describe Executable::Indenter do
       it 'indents any appended strings' do
         UI.indentation_level = 4