我正在尝试运行自定义应用程序，但会遇到多个错误。我相信主要的egs应用程序会收到错误，因为它调用了具有未定义类型的egs补丁应用程序。我无法弄清楚如何使这个工作我已经尝试多次重新编译代码有关类似问题的其他人，但似乎没有任何工作。牛仔开始听众仍未定义。
这是我收到的错误。
=CRASH REPORT==== 10-Apr-2013::21:02:00 ===
crasher:
initial call: application_master:init/4
pid: <0.106.0>
registered_name: []
exception exit: {bad_return,
{{egs_patch_app,start,[normal,[]]},
{'EXIT',
{undef,
[{cowboy,start_listener,
[{patch,11030},
10,cowboy_tcp_transport,
[{port,11030}],
egs_patch_protocol,[]],
[]},
{egs_patch_app,start_listeners,1,
[{file,"src/egs_patch_app.erl"},
{line,44}]},
{egs_patch_app,start,2,
[{file,"src/egs_patch_app.erl"},
{line,31}]},
{application_master,start_it_old,4,
[{file,"application_master.erl"},
{line,274}]}]}}}}
in function application_master:init/4 (application_master.erl, line 138)
ancestors: [<0.105.0>]
messages: [{'EXIT',<0.107.0>,normal}]
links: [<0.105.0>,<0.7.0>]
dictionary: []
trap_exit: true
status: running
heap_size: 610
stack_size: 27
reductions: 124
neighbours:
=INFO REPORT==== 10-Apr-2013::21:02:00 ===
application: egs_patch
exited: {bad_return,
{{egs_patch_app,start,[normal,[]]},
{'EXIT',
{undef,
[{cowboy,start_listener,
[{patch,11030},
10,cowboy_tcp_transport,
[{port,11030}],
egs_patch_protocol,[]],
[]},
{egs_patch_app,start_listeners,1,
[{file,"src/egs_patch_app.erl"},{line,44}]},
{egs_patch_app,start,2,
[{file,"src/egs_patch_app.erl"},{line,31}]},
{application_master,start_it_old,4,
[{file,"application_master.erl"},
{line,274}]}]}}}}
type: temporary
=CRASH REPORT==== 10-Apr-2013::21:02:00 ===
crasher:
initial call: application_master:init/4
pid: <0.75.0>
registered_name: []
exception exit: {bad_return,
{{egs_app,start,[normal,[]]},
{'EXIT',
{undef,
[{cowboy,start_listener,
[{login,12030},
10,cowboy_ssl_transport,
[{port,12030},
{certfile,"priv/ssl/servercert.pem"},
{keyfile,"priv/ssl/serverkey.pem"},
{password,"alpha"}],
egs_login_protocol,[]],
[]},
{egs_app,start_login_listeners,1,
[{file,"src/egs_app.erl"},{line,55}]},
{egs_app,start,2,
[{file,"src/egs_app.erl"},{line,38}]},
{application_master,start_it_old,4,
[{file,"application_master.erl"},
{line,274}]}]}}}}
in function application_master:init/4 (application_master.erl, line 138)
ancestors: [<0.74.0>]
messages: [{'EXIT',<0.76.0>,normal}]
links: [<0.74.0>,<0.7.0>]
dictionary: []
trap_exit: true
status: running
heap_size: 987
stack_size: 27
reductions: 185
neighbours:
=INFO REPORT==== 10-Apr-2013::21:02:00 ===
application: egs
exited: {bad_return,
{{egs_app,start,[normal,[]]},
{'EXIT',
{undef,
[{cowboy,start_listener,
[{login,12030},
10,cowboy_ssl_transport,
[{port,12030},
{certfile,"priv/ssl/servercert.pem"},
{keyfile,"priv/ssl/serverkey.pem"},
{password,"alpha"}],
egs_login_protocol,[]],
[]},
{egs_app,start_login_listeners,1,
[{file,"src/egs_app.erl"},{line,55}]},
{egs_app,start,2,
[{file,"src/egs_app.erl"},{line,38}]},
{application_master,start_it_old,4,
[{file,"application_master.erl"},
{line,274}]}]}}}}
type: temporary
以下是发生错误的文件。
egs_patch_app.erl
-module(egs_patch_app).
-behaviour(application).
-export([start/2, stop/1]). %% API.
-type application_start_type()
:: normal | {takeover, node()} | {failover, node()}.
%% API.
-spec start(application_start_type(), term()) -> {ok, pid()}.
start(_Type, _StartArgs) ->
{ok, PatchPorts} = application:get_env(patch_ports),
start_listeners(PatchPorts),
egs_patch_sup:start_link().
-spec stop(term()) -> ok.
stop(_State) ->
ok.
%% Internal.
-spec start_listeners([inet:ip_port()]) -> ok.
start_listeners([]) ->
ok;
start_listeners([Port|Tail]) ->
{ok, _Pid} = cowboy:start_listener({patch, Port}, 10,
cowboy_tcp_transport, [{port, Port}],
egs_patch_protocol, []),
start_listeners(Tail).
egs_app.erl
-module(egs_app).
-behaviour(application).
-export([start/2, stop/1]). %% API.
-include("/home/mattk/Desktop/egs-master/apps/egs/include/records.hrl").
-type application_start_type()
:: normal | {takeover, node()} | {failover, node()}.
-define(SSL_OPTIONS, [{certfile, "priv/ssl/servercert.pem"},
{keyfile, "priv/ssl/serverkey.pem"}, {password, "alpha"}]).
%% API.
-spec start(application_start_type(), term()) -> {ok, pid()}.
start(_Type, _StartArgs) ->
{ok, Pid} = egs_sup:start_link(),
application:set_env(egs_patch, patch_ports, egs_conf:read(patch_ports)),
application:start(egs_patch),
start_login_listeners(egs_conf:read(login_ports)),
{_ServerIP, GamePort} = egs_conf:read(game_server),
{ok, _GamePid} = cowboy:start_listener({game, GamePort}, 10,
cowboy_ssl_transport, [{port, GamePort}] ++ ?SSL_OPTIONS,
egs_game_protocol, []),
{ok, Pid}.
-spec stop(term()) -> ok.
stop(_State) ->
ok.
%% Internal.
-spec start_login_listeners([inet:ip_port()]) -> ok.
start_login_listeners([]) ->
ok;
start_login_listeners([Port|Tail]) ->
{ok, _Pid} = cowboy:start_listener({login, Port}, 10,
cowboy_ssl_transport, [{port, Port}] ++ ?SSL_OPTIONS,
egs_login_protocol, []),
start_login_listeners(Tail).
答案 0 :(得分：11)
这是我们的提示：
.....
{{egs_patch_app,start,[normal,[]]},
{'EXIT',
{undef,
[{cowboy,start_listener, .....
元组{egs_patch_app,start,[normal,[]]}告诉我们错误发生在egs_patch_app:start/2。原子EXIT是进程退出时发送的通知消息的标记，或者是catch error(someerror)之类的表达式的结果。现在我们来到有趣的部分。 undef表示尝试调用未定义的函数。如果函数名称/ Arity与任何已知函数不匹配，则该函数未定义。在这种情况下，未定义的函数是cowboy:start_listener()。
问题再一次，问题是牛仔已经进化而egs没有。牛仔API的重大变化使两者不相容。由于egs的最后一次更改大约是一年前（假设您使用的是essen的分支），您可以尝试通过将相应的rebar.config行更改为以下内容来恢复旧的Cowboy标记：
{cowboy, ".*", {git, "git://github.com/extend/cowboy.git", {tag, "0.6.0"}}
注意"HEAD"如何更改为{tag, "0.6.0"}。牛仔参考可能必须在多个应用程序中更改（至少egs和egs_patch）。您可能需要先清除deps/。
Erlang错误消息可能难以解析，但作为一般经验法则，您应该留意几个原子：
case_clause，表示case表达式中没有匹配的条款。function_clause，意思是没有函数子句与参数匹配。undef，如上所述，意味着无法解析对外部（非本地模块）功能的调用。badarg，这是Erlang的“非法论证”例外。badarith，一个偷偷摸摸的混蛋，有时会在您将变量名称输入算术表达式中的原子时出现，例如1/x而不是1/X。要了解有关Erlang错误处理机制的更多信息，请阅读the docs。