anchor.diff:  -module(rebar_utils).
   
   -export([get_cwd/0,
  -         get_os/0]).
  +         is_arch/1,
  +         get_os/0,
  +         sh/2,
  +         sh_failfast/2]).
   
  +-include("rebar.hrl").
   
   %% ====================================================================
   %% Public API
  
positive.code:         nomatch ->
             match_first(Rest, Val)
      end.
  
negative.code:     Dir.
  
  
  is_arch(ArchRegex) ->
      Arch = erlang:system_info(system_architecture),
      case re:run(Arch, ArchRegex, [{capture, none}]) of
          match ->
              true;
          nomatch ->
              false
      end.
  
  get_os() ->
      Arch = erlang:system_info(system_architecture),
      case match_first([{"linux", linux}, {"darwin", darwin}], Arch) of
  