Check for the existence of Rubinius::LIB_PATH and actually tell the user in case of error

kernel/alpha.rb

@@ -171,7 +171,7 @@ def kind_of?(cls)
   # This method may be overridden, and is often used to provide dynamic
   # behaviour. An overriding version should call super if it fails to
   # resolve the message. This practice ensures that the default version
-  # will called if all else fails.
+  # will be called if all else fails.
   #
   def method_missing(meth, *args)
     raise NoMethodError, "Unable to send '#{meth}' on '#{self}' (#{self.class})"
@@ -453,7 +453,7 @@ def const_missing(name)
 
   # Set Module's direct superclass.
   #
-  # The corresponding 'getter' #superclass method defined
+  # The corresponding 'getter' #superclass method is defined
   # in class.rb, because it is more complex than a mere
   # accessor
   #

kernel/loader.rb

@@ -74,17 +74,14 @@ def preamble
     def system_load_path
       @stage = "setting up system load path"
 
-      @main_lib = nil
-
-      if env_lib = ENV['RBX_LIB']
-        @main_lib = File.expand_path(env_lib) if File.exists?(env_lib)
-      end
-
-      # Use the env version if it's set.
-      @main_lib = Rubinius::LIB_PATH unless @main_lib
+      if env_lib = ENV['RBX_LIB'] and File.exists?(env_lib)
+        @main_lib = File.expand_path(env_lib)
+      else
+        # use configured library path and check its existence
+        @main_lib = Rubinius::LIB_PATH
 
-      unless @main_lib
-        STDERR.puts <<-EOM
+        unless File.exists?(@main_lib)
+          STDERR.puts <<-EOM
 Rubinius was configured to find standard library files at:
 
   #{@main_lib}
@@ -93,21 +90,23 @@ def system_load_path
 
 Set the environment variable RBX_LIB to the directory
 containing the Rubinius standard library files.
-        EOM
+          EOM
+        end
       end
 
       @main_lib_bin = File.join @main_lib, "bin"
       Rubinius.const_set :PARSER_EXT_PATH, "#{@main_lib}/ext/melbourne/rbx/melbourne20"
 
       # This conforms more closely to MRI. It is necessary to support
       # paths that mkmf adds when compiling and installing native exts.
-      additions = []
-      additions << Rubinius::SITE_PATH
-      additions << "#{Rubinius::SITE_PATH}/#{Rubinius::CPU}-#{Rubinius::OS}"
-      additions << Rubinius::VENDOR_PATH
-      additions << "#{Rubinius::VENDOR_PATH}/#{Rubinius::CPU}-#{Rubinius::OS}"
-      additions << "#{@main_lib}/#{Rubinius::RUBY_LIB_VERSION}"
-      additions << @main_lib
+      additions = [
+        Rubinius::SITE_PATH,
+        "#{Rubinius::SITE_PATH}/#{Rubinius::CPU}-#{Rubinius::OS}",
+        Rubinius::VENDOR_PATH,
+        "#{Rubinius::VENDOR_PATH}/#{Rubinius::CPU}-#{Rubinius::OS}",
+        "#{@main_lib}/#{Rubinius::RUBY_LIB_VERSION}",
+        @main_lib,
+      ]
       additions.uniq!
 
       $LOAD_PATH.unshift(*additions)
@@ -160,7 +159,7 @@ def show_syntax_errors(syns)
       end
     end
 
-    # Checks if a subcammand with basename +base+ exists. Returns the full
+    # Checks if a subcommand with basename +base+ exists. Returns the full
     # path to the subcommand if it does; otherwise, returns nil.
     def find_subcommand(base)
       command = File.join @main_lib_bin, "#{base}.rb"