Here is the error I receive when calling snmp_test_manager:start_link.  On line 133 of that file, in do_init, there is the following line:

{ok, Pid} = snmpm:start_link(MgrOpts)

This results in a badmatch error because snmpm:start_link returns the atom ok, and not a tuple, as seen below (line 155, snmpm.erl):

start_link(Opts) ->
    %% This start the manager top supervisor, which in turn
    %% starts the other processes.
    {ok, _} = snmpm_supervisor:start_link(normal, Opts),
    ok.


Full traceback here:

Eshell V5.9.1  (abort with ^G)
1> snmp_test_manager:start_link([{options, [{config, [{dir,"/tmp"}, {db_dir, "/tmp"}]}]}, {agent_config, []}, {agent_target, "127.0.0.1"}]).
** exception exit: {case_clause,
                       {'EXIT',
                           {{badmatch,ok},
                            [{snmp_test_manager,do_init,1,
                                 [{file,"snmp_test_manager.erl"},{line,133}]},
                             {snmp_test_manager,init,1,
                                 [{file,"snmp_test_manager.erl"},{line,123}]},
                             {gen_server,init_it,6,[{file,"gen_server.erl"},{line,304}]},
                             {proc_lib,init_p_do_apply,3,
                                 [{file,"proc_lib.erl"},{line,227}]}]}}}
     in function  snmp_test_manager:init/1 (snmp_test_manager.erl, line 123)
     in call from gen_server:init_it/6 (gen_server.erl, line 304)
     in call from proc_lib:init_p_do_apply/3 (proc_lib.erl, line 227)
2>
=ERROR REPORT==== 26-Mar-2014::08:35:05 ===
** Generic server snmpm_supervisor terminating
** Last message in was {'EXIT',<0.34.0>,
                        {{case_clause,
                          {'EXIT',
                           {{badmatch,ok},
                            [{snmp_test_manager,do_init,1,
                              [{file,"snmp_test_manager.erl"},{line,133}]},
                             {snmp_test_manager,init,1,
                              [{file,"snmp_test_manager.erl"},{line,123}]},
                             {gen_server,init_it,6,
                              [{file,"gen_server.erl"},{line,304}]},
                             {proc_lib,init_p_do_apply,3,
                              [{file,"proc_lib.erl"},{line,227}]}]}}},
                         [{snmp_test_manager,init,1,
                           [{file,"snmp_test_manager.erl"},{line,123}]},
                          {gen_server,init_it,6,
                           [{file,"gen_server.erl"},{line,304}]},
                          {proc_lib,init_p_do_apply,3,
                           [{file,"proc_lib.erl"},{line,227}]}]}}
** When Server state == {state,
                         {local,snmpm_supervisor},
                         one_for_all,
                         [{child,<0.46.0>,snmpm_server_sup,
                           {snmpm_server_sup,start_link,
                            [normal,
                             [{config,[{dir,"/tmp"},{db_dir,"/tmp"}]}]]},
                           transient,2000,supervisor,
                           [snmpm_server_sup,supervisor]},
                          {child,<0.45.0>,snmpm_misc_sup,
                           {snmpm_misc_sup,start_link,[]},
                           transient,2000,supervisor,
                           [snmpm_misc_sup,supervisor]},
                          {child,<0.37.0>,snmpm_config,
                           {snmpm_config,start_link,
                            [[{config,[{dir,"/tmp"},{db_dir,"/tmp"}]}]]},
                           transient,2000,worker,
                           [snmpm_config,gen_server]}],
                         undefined,0,3600,[],snmpm_supervisor,
                         [normal,[{config,[{dir,"/tmp"},{db_dir,"/tmp"}]}]]}
** Reason for termination ==
** {{case_clause,
        {'EXIT',
            {{badmatch,ok},
             [{snmp_test_manager,do_init,1,
                  [{file,"snmp_test_manager.erl"},{line,133}]},
              {snmp_test_manager,init,1,
                  [{file,"snmp_test_manager.erl"},{line,123}]},
              {gen_server,init_it,6,[{file,"gen_server.erl"},{line,304}]},
              {proc_lib,init_p_do_apply,3,
                  [{file,"proc_lib.erl"},{line,227}]}]}}},
    [{snmp_test_manager,init,1,[{file,"snmp_test_manager.erl"},{line,123}]},
     {gen_server,init_it,6,[{file,"gen_server.erl"},{line,304}]},
     {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}]}