Application module `start` function not called?

Hmmm

In fail case:

iex(2)> Application.started_applications()
[
{:myapp, [], []},
{:hex, ~c"hex", ~c"2.2.2"},
{:inets, ~c"INETS  CXC 138 49", ~c"9.4.2"},
{:ssl, ~c"Erlang/OTP SSL application", ~c"11.4"},
{:public_key, ~c"Public key infrastructure", ~c"1.18.3"},
{:asn1, ~c"The Erlang ASN1 compiler version 5.4.2", ~c"5.4.2"},
{:crypto, ~c"CRYPTO", ~c"5.7"},
{:mix, ~c"mix", ~c"1.18.4"},
{:iex, ~c"iex", ~c"1.18.4"},
{:elixir, ~c"elixir", ~c"1.18.4"},
{:compiler, ~c"ERTS  CXC 138 10", ~c"9.0.2"},
{:stdlib, ~c"ERTS  CXC 138 10", ~c"7.1"},
{:kernel, ~c"ERTS  CXC 138 10", ~c"10.4"}
]

iex(4)> Application.ensure_started(:phoenix_live_reload)
{:error, {:not_started, :logger}}
iex(5)> Application.ensure_started(:logger)
:ok
iex(6)> Application.ensure_started(:phoenix_live_reload)
{:error, {:not_started, :phoenix}}
iex(7)> Application.ensure_started(:phoenix)
{:error, {:not_started, :eex}}
iex(8)> Application.ensure_started(:eex)
:ok
iex(9)> Application.ensure_started(:phoenix)
{:error, {:not_started, :plug}}
iex(10)> Application.ensure_started(:plug)
{:error, {:not_started, :mime}}
iex(11)> Application.ensure_started(:mime)
:ok
iex(12)> Application.ensure_started(:plug)
{:error, {:not_started, :plug_crypto}}
iex(13)> Application.ensure_started(:plug_crypto)
:ok
iex(14)> Application.ensure_started(:plug)
{:error, {:not_started, :telemetry}}
iex(15)> Application.ensure_started(:telemetry)
:ok
iex(16)> Application.ensure_started(:plug)
:ok
iex(17)> Application.ensure_started(:phoenix)
{:error, {:not_started, :phoenix_pubsub}}
iex(18)> Application.ensure_started(:phoenix_pubsub)
:ok
iex(19)> Application.ensure_started(:phoenix)
{:error, {:not_started, :phoenix_template}}
iex(20)> Application.ensure_started(:phoenix_templete)
{:error, {~c"no such file or directory", ~c"phoenix_templete.app"}}

Update: in the end I was able to start them all and made sure that the file is there. So I do not know if this is related (or if I’m doing it correctly anyway).

Let us know when you dig the problem out. Should be something trivial that the tooling does not yell at you for but must be this or that, I presume.

Yes, I’ve redacted the true app name and redacted the paths with the app name. However, there is not one line in patters list that would cause the issue (I’ve checked). I have to remove this whole config section to see the apps starting. So I think it is not about the dir/files the inotify observes.

And yes, with new/clean project, the live_reload isn’t blocking the startup. In new project and in my project I’m using the same versions of the packages (e.g. file_system). I’ve also checked the code generated in new project - it looks the same (only some patters are different).

Update: empty patters also helps! So I do not have to remove the whole section from config file.

I take it that you redacted the app name and module namespace in the snippet above and they’re not the same in the real code? Just making sure.

Also does this code look the same in a freshly generated project?

It seems that the issue is with:

# Watch static and templates for browser reloading.
config :myapp, MyAppWeb.Endpoint,
  live_reload: [
    patterns: [
      ~r"priv/static/.*(js|css|png|jpeg|jpg|gif|svg)$",
      ~r"priv/gettext/.*(po)$",
      ...
    ]
  ]

Without this feature configured, the dev comes up. I wonder what might be the issue here. I will double check my paths here.

diff _build/{dev,prod}/lib/<app_name>/ebin/<app_name>.app

Then the culprit should be config/prod.exs or config/runtime.exs or any code that branches on the environment variables.

That is odd. I don’t know off the top of my head anything that would cause that behavior, though perhaps someone else will think of something.

Given that the behavior is different between environments you may want to comb through the configs for anything that could be different, though again I’m not sure what that might be.

As for your question about what happens when the application starts, it’s described quite thoroughly in the Application docs.

@garrison none of the children are started. The function is not called/entered.

@jswanner even with raise “here” it will not stop it. I’m using iex -S mix phx.server with some env variables.

Note that with MIX_ENV=prod it works, every time. With MIX_ENV=dev it does not. Only this MIX_ENV is different in invocation.

I believe @garrison is trying to get at is if any of the children in your application are running, if so then your application is running, and your endpoint is an easy one to test if it’s running.

How are you running your application? mix phx.server from the terminal, or some other way? Is it possible something is swallowing that IO you are using to debug? Instead of IO.inspect("here") you can try raise "here"