unable to run when from escript

[binarytemple]

Hi, experimenting with various Elixir time libraries - https://github.com/binarytemple/poc_elixir_calendars/tree/escript_broken

Everything works fine in IEX session. But when escripted there is a crash at startup within the Tzdata application.

I build like so:

mix do deps.compile, escript.build && ./poc_elixir_calendars

The error (formatted) is the following:

{:error, {:shutdown,
    {:failed_to_start_child, Tzdata.EtsHolder,
     {%ArgumentError{message: "unknown application: :tzdata"},
    [
    {Application, :app_dir, 1, [file: 'lib/application.ex', line: 372]},
    {Application, :app_dir, 2, [file: 'lib/application.ex', line: 381]},
    {Tzdata.EtsHolder, :release_dir, 0, [file: 'lib/tzdata/ets_holder.ex', line: 86]},
    {Tzdata.EtsHolder, :make_sure_a_release_dir_exists, 0,
     [file: 'lib/tzdata/ets_holder.ex', line: 70]},
    {Tzdata.EtsHolder, :make_sure_a_release_is_on_file, 0,
     [file: 'lib/tzdata/ets_holder.ex', line: 64]},
    {Tzdata.EtsHolder, :init, 1, [file: 'lib/tzdata/ets_holder.ex', line: 10]},
    {:gen_server, :init_it, 6, [file: 'gen_server.erl', line: 328]},
    {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 240]
    }
    ]}}}}

The escript contains all the Tzdata files, including the ETS dump, '2016c.ets':

 % zipinfo poc_elixir_calendars | egrep -i '(ets|tz)'
-rw----     2.0 fat     1079 b- defN 31-Jul-16 21:14 tzdata.app
-rw----     2.0 fat    11516 b- defN 31-Jul-16 21:14 Elixir.Calendar.DateTime.TzPeriod.beam
-rw----     2.0 fat     5232 b- defN 31-Jul-16 21:14 Elixir.Tzdata.ReleaseUpdater.beam
-rw----     2.0 fat     9372 b- defN 31-Jul-16 21:14 Elixir.Tzdata.DataLoader.beam
-rw----     2.0 fat     3504 b- defN 31-Jul-16 21:14 Elixir.Tzdata.TableParser.beam
-rw----     2.0 fat  3397782 b- defN 31-Jul-16 21:14 2016c.ets
-rw----     2.0 fat     9932 b- defN 31-Jul-16 21:14 Elixir.Tzdata.Parser.beam
-rw----     2.0 fat    12232 b- defN 31-Jul-16 21:14 Elixir.Tzdata.beam
-rw----     2.0 fat     8292 b- defN 31-Jul-16 21:14 Elixir.Tzdata.DataBuilder.beam
-rw----     2.0 fat     5060 b- defN 31-Jul-16 21:14 Elixir.Tzdata.ReleaseReader.beam
-rw----     2.0 fat     3196 b- defN 31-Jul-16 21:14 Elixir.Tzdata.BasicDataMap.beam
-rw----     2.0 fat     6116 b- defN 31-Jul-16 21:14 Elixir.Tzdata.ParserOrganizer.beam
-rw----     2.0 fat     7640 b- defN 31-Jul-16 21:14 Elixir.Tzdata.EtsHolder.beam
-rw----     2.0 fat    19732 b- defN 31-Jul-16 21:14 Elixir.Tzdata.Util.beam
-rw----     2.0 fat     9368 b- defN 31-Jul-16 21:14 Elixir.Tzdata.FarFutureDynamicPeriods.beam
-rw----     2.0 fat     5204 b- defN 31-Jul-16 21:14 Elixir.Tzdata.LeapSecParser.beam
-rw----     2.0 fat     2236 b- defN 31-Jul-16 21:14 Elixir.Tzdata.App.beam
-rw----     2.0 fat     1088 b- defN 31-Jul-16 21:14 Elixir.Tzdata.TableData.beam
-rw----     2.0 fat    12828 b- defN 31-Jul-16 21:14 Elixir.Tzdata.PeriodBuilder.beam

Any suggestions?

[lau]

Hi Bryan

Tzdata versions 0.5 and higher don't work with escripts currently. Because escript don't work with ETS tables. AFAIK in future Elixir versions they will.
Try specifying tzdata version ~> 0.1.7 in your deps file. That should work.

-- Lau

[binarytemple]

Thanks Lau. Changed version as suggested. Worked.

[kenbod]

Thanks for this discussion. It helped me workaround the same issue. I'm now motivated to learn how I can launch my application without using escript so I can avoid having to use an old version of tzdata in my project.

[binarytemple]

@kenbod - some more discussion around the loading data when disconnected from the internet can be found here - #25 - perhaps it is possible to stay with escript but specify a data file load path outside the escript.

[kenbod]

Thanks, I'll check the "data file load path" option out if I find I need a newer version of tzdata.

[carlogilmar]

I try to use tzdata as transitive dependency from Calendar with escript and failed again... I had to downgrade