[erlang-questions] rebar and the observer application.

[Tuncer Ayaz]

On Fri, May 4, 2012 at 7:33 PM, Red Davies wrote:
> Greetings,
>
> I'm still very new, please forgive me if this is an easy question to answer.
>
> I'm trying to use observer to view my application VM.  The application is
> run as follows:
>
> rel/xeuler1/bin/xeuler1 console
> Exec: /home/red/projects/dev--/xeuler1/rel/xeuler1/erts-5.9/bin/erlexec
> -boot /home/red/projects/dev--/xeuler1/rel/xeuler1/releases/1/xeuler1 -mode
> embedded -config
> /home/red/projects/dev--/xeuler1/rel/xeuler1/releases/1/sys.config
> -args_file /home/red/projects/dev--/xeuler1/rel/xeuler1/releases/1/vm.args
> -- console
> Root: /home/red/projects/dev--/xeuler1/rel/xeuler1
> Erlang R15B (erts-5.9) [source] [64-bit] [smp:4:4] [async-threads:0]
> [kernel-poll:false]
>
> Eshell V5.9  (abort with ^G)
> (xeuler1@REDACTED)1>
>
> I run up a second erlang instance with my observer application as follows:
> erl -name observer -hidden -setcookie xeuler1 -run observer
>
> The nodes are able to communicate:
> (observer@REDACTED)1> net:ping(xeuler1@REDACTED).
> pong
>
> However, when I try to connect to the remote node using the observer UI I
> get the following output:
> =ERROR REPORT==== 4-May-2012::13:22:17 ===
>     node: 'xeuler1@REDACTED'
>     call: {observer_backend,sys_info,[]}
>     reason: {badrpc,
>                 {'EXIT',
>                     {undef,
>                         [{observer_backend,sys_info,[],[]},
>                          {rpc,'-handle_call_call/6-fun-0-',5,
>                              [{file,"rpc.erl"},{line,203}]}]}}}
>
> So, my understanding of the problem is that my reltool generated environment
> doesn't have a deployed version of observer.  I've added it to
> reltool.config the best I can understand it and a find rel/ | grep observer
> does see observer related files in there.

You should add _only_ appmon and runtime_tools to the release for
xeuler1.

> If I try to run observer:start() from my actual xeuler1 VM then it hangs
> indefinately.

Although you shouldn't run observer on xeuler1, does it stop hanging
if you add wx?

> Any advice on how I to debug this?

Use the failed
rpc:call('xeuler1@REDACTED', observer, sys_info, [])
as a hint for which app is missing.