Error when following Phoenix Walkthrough Documentation

[BryanJBryce]

When I get to the end of the Phoenix walkthrough documentation it reads:

At this point, you can run your release using one of the three commands listed in the output.

But when I try to run in foreground or any other method I get this error output:

$ rel/stirling/bin/stirling foreground

=CRASH REPORT==== 5-Sep-2016::21:56:37 ===
  crasher:
    initial call: Elixir.Phoenix.CodeReloader.Server:init/1
    pid: <0.1113.0>
    registered_name: []
    exception exit: {undef,
                        [{'Elixir.Mix.Project',config,[],[]},
                         {'Elixir.Phoenix.CodeReloader.Server',init,1,
                             [{file,"lib/phoenix/code_reloader/server.ex"},
                              {line,29}]},
                         {gen_server,init_it,6,
                             [{file,"gen_server.erl"},{line,328}]},
                         {proc_lib,init_p_do_apply,3,
                             [{file,"proc_lib.erl"},{line,240}]}]}
      in function  gen_server:init_it/6 (gen_server.erl, line 352)
    ancestors: ['Elixir.Stirling.Endpoint','Elixir.Stirling.Supervisor',
                  <0.1087.0>]
    messages: []
    links: [<0.1104.0>]
    dictionary: []
    trap_exit: false
    status: running
    heap_size: 610
    stack_size: 27
    reductions: 127
  neighbors:


=SUPERVISOR REPORT==== 5-Sep-2016::21:56:37 ===
     Supervisor: {local,'Elixir.Stirling.Endpoint'}
     Context:    start_error
     Reason:     {undef,
                     [{'Elixir.Mix.Project',config,[],[]},
                      {'Elixir.Phoenix.CodeReloader.Server',init,1,
                          [{file,"lib/phoenix/code_reloader/server.ex"},
                           {line,29}]},
                      {gen_server,init_it,6,
                          [{file,"gen_server.erl"},{line,328}]},
                      {proc_lib,init_p_do_apply,3,
                          [{file,"proc_lib.erl"},{line,240}]}]}
     Offender:   [{pid,undefined},
                  {id,'Elixir.Phoenix.CodeReloader.Server'},
                  {mfargs,
                      {'Elixir.Phoenix.CodeReloader.Server',start_link,
                          [stirling,'Elixir.Stirling.Endpoint',
                           [gettext,phoenix,elixir],
                           [{name,'Elixir.Stirling.Endpoint.CodeReloader'}]]}},
                  {restart_type,permanent},
                  {shutdown,5000},
                  {child_type,worker}]


=SUPERVISOR REPORT==== 5-Sep-2016::21:56:37 ===
     Supervisor: {local,'Elixir.Stirling.Supervisor'}
     Context:    start_error
     Reason:     {shutdown,
                     {failed_to_start_child,
                         'Elixir.Phoenix.CodeReloader.Server',
                         {undef,
                             [{'Elixir.Mix.Project',config,[],[]},
                              {'Elixir.Phoenix.CodeReloader.Server',init,1,
                                  [{file,
                                       "lib/phoenix/code_reloader/server.ex"},
                                   {line,29}]},
                              {gen_server,init_it,6,
                                  [{file,"gen_server.erl"},{line,328}]},
                              {proc_lib,init_p_do_apply,3,
                                  [{file,"proc_lib.erl"},{line,240}]}]}}}
     Offender:   [{pid,undefined},
                  {id,'Elixir.Stirling.Endpoint'},
                  {mfargs,{'Elixir.Stirling.Endpoint',start_link,[]}},
                  {restart_type,permanent},
                  {shutdown,infinity},
                  {child_type,supervisor}]


=CRASH REPORT==== 5-Sep-2016::21:56:37 ===
  crasher:
    initial call: application_master:init/4
    pid: <0.1086.0>
    registered_name: []
    exception exit: {{shutdown,
                      {failed_to_start_child,'Elixir.Stirling.Endpoint',
                       {shutdown,
                        {failed_to_start_child,
                         'Elixir.Phoenix.CodeReloader.Server',
                         {undef,
                          [{'Elixir.Mix.Project',config,[],[]},
                           {'Elixir.Phoenix.CodeReloader.Server',init,1,
                            [{file,"lib/phoenix/code_reloader/server.ex"},
                             {line,29}]},
                           {gen_server,init_it,6,
                            [{file,"gen_server.erl"},{line,328}]},
                           {proc_lib,init_p_do_apply,3,
                            [{file,"proc_lib.erl"},{line,240}]}]}}}}},
                     {'Elixir.Stirling',start,[normal,[]]}}
      in function  application_master:init/4 (application_master.erl, line 134)
    ancestors: [<0.1085.0>]
    messages: [{'EXIT',<0.1087.0>,normal}]
    links: [<0.1085.0>,<0.974.0>]
    dictionary: []
    trap_exit: true
    status: running
    heap_size: 610
    stack_size: 27
    reductions: 124
  neighbors:
[info] Application stirling exited: Stirling.start(:normal, []) returned an error: shutdown: failed to start child: Stirling.Endpoint
    ** (EXIT) shutdown: failed to start child: Phoenix.CodeReloader.Server
        ** (EXIT) an exception was raised:
            ** (UndefinedFunctionError) function Mix.Project.config/0 is undefined (module Mix.Project is not available)
                Mix.Project.config()
                (phoenix) lib/phoenix/code_reloader/server.ex:29: Phoenix.CodeReloader.Server.init/1
                (stdlib) gen_server.erl:328: :gen_server.init_it/6
                (stdlib) proc_lib.erl:240: :proc_lib.init_p_do_apply/3
{"Kernel pid terminated",application_controller,"{application_start_failure,stirling,{{shutdown,{failed_to_start_child,'Elixir.Stirling.Endpoint',{shutdown,{failed_to_start_child,'Elixir.Phoenix.CodeReloader.Server',{undef,[{'Elixir.Mix.Project',config,[],[]},{'Elixir.Phoenix.CodeReloader.Server',init,1,[{file,\"lib/phoenix/code_reloader/server.ex\"},{line,29}]},{gen_server,init_it,6,[{file,\"gen_server.erl\"},{line,328}]},{proc_lib,init_p_do_apply,3,[{file,\"proc_lib.erl\"},{line,240}]}]}}}}},{'Elixir.Stirling',start,[normal,[]]}}}"}
/Users/bryan/war/stirling/rel/stirling/releases/0.0.1/stirling.sh: line 550: 16920 User defined signal 2: 31 "$@" -- ${1+$ARGS}
Shutting down node cleanly..
Node is not running!