Support for `mix release` releases

[michaeljones]

I have been using this project to extend a Phoenix app with a plug that runs requests through a Wisp/Gleam handler and only passes them on to Phoenix. It has been great and exciting and working well with the recommended mix_gleam setup and mix phx.server.

Unfortunately when I try to do a mix release and run that, I get the following error:

#PID<0.2848.0> running ContactStackWeb.Endpoint (connection #PID<0.2846.0>, stream id 2) terminated
Server: www.contact-stack.com:80 (http)
Request: GET /api/v1/tasks
** (exit) exited in: :pgo_pool.checkout(:pog_pool_838, [])
    ** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started - {{2024, 11, 18}, {18, 58, 13, 129}}

I create a Discord question about it (https://discord.com/channels/768594524158427167/1308172468422185020) and my understanding of the response is that erlang/BEAM releases are quite complex things and mix_gleam doesn't necessary support any release path ways.

I wanted to double check that that is the case. My guess is that it is a good solution for relying on Gleam library code but not necessarily dependencies with their own applications? I've done a little reading up on erlang releases but it seems like a complex area (which is why it might not be supported) but at the same time it seems like mix_gleam does help mix put various applications into the correct app and rel files so I'm not sure what might be missing.

If it is the case that certain kinds of Gleam development isn't supported in releases via this tool then I suggested in the Discord that maybe the README here should mention that? Does that seem like a good idea?

[lpil]

Unless this is a quick easy fix for someone I don't think this would be a good use of time compared to having releases in the Gleam build tool or having Gleam support in Mix.