Here’s the update:

1. I made distillery a runtime: false dependency. This also removes the need for mix to be in the release. This dropped the size by 4.5%, but it felt good to not include the build tools. I’ll obviously need to reconsider if we start using the config providers
2. Stripping the .beam files trimmed the firmware by 35%! Everything (Linux kernel, beam.smp, drivers, wifi firmware, bootloaders, and the OTP release) are now in a 15.2 MB package.
3. @mobileoverlord had to make some PRs to Distillery and Shoehorn, so these numbers aren’t easy to reproduce yet. They also include unreleased updates to nerves_system_br.

I’m not out of the woods with size, but I’m going to savor this improvement over the Thanksgiving holiday here. I also want to see if I can live with the stripped beams.

Here are some stats:

After stripping the beams:

$ du -ks * | sort -nr
1632   elixir-1.7.4
1160   stdlib-3.6
668     kernel-6.1
512     compiler-7.2.7
356     asn1-5.0.7
312     ssl-9.0.3
284     ssh-4.7.1
264     public_key-1.6.3
160     iex-1.7.4
152     runtime_tools-1.13.1
148     sasl-3.2.1
132     crypto-4.3.3
104     socket-0.3.13
100     nerves_runtime-0.8.0

Post strip, here’s example contents of a .beam file (this one is the current winner on size in the Elixir app)

iex(9)> :beam_lib.info('/srv/erlang/lib/elixir-1.7.4/ebin/Elixir.Base')  
[
  file: '/srv/erlang/lib/elixir-1.7.4/ebin/Elixir.Base.beam',
  module: Base,
  chunks: [
    {'Line', 20, 636},
    {'AtU8', 664, 1642},
    {'Code', 2316, 230760},
    {'StrT', 233084, 45},
    {'ImpT', 233140, 232},
    {'ExpT', 233380, 400},
    {'LitT', 233788, 218}
  ]
]

I would assume that means that line number info is still present, but it looks too small to worry about.

Specifically the strip_debug_info is an option for Distillery Configuring Distillery - Distillery Documentation.

Would be cool with an article discussing the ways to reduce size.

I’m wondering if incremental updates would help you as well. I often update my releases not by uploading the whole thing, but by using rsync to just upload what’s changed.