Rebar fails to compile application with badarg on is_app_available

Question

My erlang application named "myapp1" builds fine using rebar as far as I do not include another erlang application "my_other_app" under its dependencies (deps). Once I add it to my dependencies, and specify it under rebar.config, its build fails in error as such:

> rebar compile
Uncaught error in rebar_core: {'EXIT',
                               {badarg,
                                [{re,run,[0.9,".*",[{capture,none}]],[]},
                                 {rebar_deps,is_app_available,5,
                                  [{file,"src/rebar_deps.erl"},{line,418}]},
                                 {rebar_deps,find_dep_in_dir,3,
                                  [{file,"src/rebar_deps.erl"},{line,380}]},
                                 {rebar_deps,find_dep,3,
                                  [{file,"src/rebar_deps.erl"},{line,362}]},
                                 {rebar_deps,find_deps,4,
                                  [{file,"src/rebar_deps.erl"},{line,345}]},
                                 {rebar_deps,preprocess,2,
                                  [{file,"src/rebar_deps.erl"},{line,63}]},
                                 {rebar_core,acc_modules,5,
                                  [{file,"src/rebar_core.erl"},{line,492}]},
                                 {rebar_core,process_dir1,6,
                                  [{file,"src/rebar_core.erl"},{line,195}]}]}}

The rebar.config is

%%-*- mode: erlang -*-

{deps, [
          {webmachine, "1.10.*", {git, "git://github.com/basho/webmachine", "HEAD"}},
          amqp_client,
          rabbit_common,
          my_other_app
       ]
}.

The tree structure is as such:

myapp1
    -src/...
    -ebin/...
    -rebar.config
    -deps/
        -webmachine
        -mochiweb
        -my_other_app
              -src/...
              -ebin/...
              -include/...

As far as I remove the my_other_app from the rebar.config, everything works (except that the application does not function given the fact I am excluding a required depdency, but at least it compiles after I comment the code that uses that dependency.

I am trying to understand what the "is_app_available" function does in rebar, as my my_other_app is indeed an OTP application, but it is not started at the time I compile with rebar (it will be started by the myapp1 itself once some services start.

Answer 1

Found the issue...

The dependency application had a Vsn (version) to its my_other_app.app.src file that was not a string ( numeric value instead ). This caused rebar to error. Certainly rebar could have a more friendly capture/error message...

Therefore, make sure to verify the {vsn, "1.1"} tag, so it has a string rather than decimal/numeric.

{application, my_other_app, [
    {description, "my other appapplication"},
    {vsn, "1.1"},
    {applications, [kernel, stdlib]},
    {modules, [.........etc.etc.etc......]},
    {registered, [my_other_app]},
    {mod,{ my_other_app, {true} } }
]}.