tweaks for style

lib/vagrant/util/subprocess.rb

@@ -27,11 +27,12 @@ def self.execute(*command, &block)
       def initialize(*command)
         @options = command.last.is_a?(Hash) ? command.pop : {}
         @command = command
-        @command[0] = Which.which(@command[0]) unless File.exists? @command[0]
-        unless @command[0]
-          raise Errors::CommandUnavailableWindows if Platform.windows?
-          raise Errors::CommandUnavailable
+        @command[0] = Which.which(@command[0]) if !File.file? @command[0]
+        if !@command[0]
+          raise Errors::CommandUnavailableWindows, file: command[0] if Platform.windows?
+          raise Errors::CommandUnavailable, file: command[0]
         end
+
         @logger  = Log4r::Logger.new("vagrant::util::subprocess")
       end
 

templates/locales/en.yml

@@ -167,8 +167,14 @@ en:
         available below.
 
         %{help}
-      command_unavailable: "command binary could not be found. Is this application installed?"
-      command_unavailable_windows: "command executable not found in any directories in the %PATH% variable."
+      command_unavailable: |-
+        The executable '%(file)' Vagrant is trying to run was not
+        found in the PATH variable. This is an error. Please verify
+        this software is installed and on the path.
+      command_unavailable_windows: |-
+        The executable '%(file)' Vagrant is trying to run was not
+        found in the %PATH% variable. This is an error. Please verify
+        this software is installed and on the path.
       config_invalid: |-
         There are errors in the configuration of this machine. Please fix
         the following errors and try again: