If I start the Elixir repl with iex, I can start the observer by :observer.start(). So far, so good. If a create an app with mix new myapp and start it with iex -S mix, attempting to start the observer results in the following error: ** (UndefinedFunctionError) function :observer.start/0 is undefi…

Correct. I also submitted a bug report upstream.

Seems that not only :observer is an issue. After upgrading to elixir 1.15 and rebuilding project dialyzer stopped working as well. mix dialyzer now gives this: Error loading poison, dependency list may be incomplete. {~c"no such file or directory", ~c"poison.app"} Error loading table, dependency…

That’s a Dialyxir issue and there are open PRs under consideration!

After adding :observer, :wx and :runtime_tools to :extra_application I get: [notice] Application runtime_tools exited: :stopped ** (Mix) Could not start application observer: could not find application file: observer.app

Which OS are you using? Certain operating systems break Erlang into several packages, you need to make sure those packages are installed.

Some guy called Jose Valim said the same thing on stack overflow eight years ago [coderVishal] Observer is not available - Elixir elixir asked by coderVishal on 04:22AM - 08 Sep 15 UTC

Will adding :observer and :wx be problematic for production releases where we are not installing the underlying wx libraries as part of our docker image?

I am having a similar problem, I am using Sonoma 14.1.1 (m1), erlang 25.3.2.7, the issues boils in my case down to wxwidget compilation with erlang. I have not been able to compile erlang passing the --enable-wx --with-wx-config option. it keep failing with the next: clang: error: linker command …

it was an issue in the build for Mac with that erlang version, take a Look at the issue

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Cannot start observer: (UndefinedFunctionError) function :observer.start/0 is undefined

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godzila September 27, 2023, 12:46pm 13

That would be Ubuntu 22.04