The issue appears to have something to do with the version of wxmac which you might be running. Updating your version of wxmac and then reinstalling Erlang appears to solve the problem.
Here's a link to a gist which will show what my wxmac formula looks like: https://gist.github.com/douglasgreyling/92c673316c0a69a7d67fb5547fd81314
All I did was:

1. Update the url to: https://github.com/wxWidgets/wxWidgets/releases/download/v3.1.5/wxWidgets-3.1.5.tar.bz2
2. Update the sha256 to: d7b3666de33aa5c10ea41bb9405c40326e1aeb74ee725bb88f90f1d50270a224
3. Remove --enable-webkit from the install args
4. Add --enable-compat28 to the install args
   After that I ran brew reinstall --build-from-source wxmac
   Once that was done I had to reinstall Erlang.
   I had asdf installed so all I had to do was:

asdf plugin remove erlang
asdf plugin-add erlang
asdf install erlang latest

If you have Elixir installed then you can run iex , and then run :observer.start() and then you should be greeted with Observer which looks like it should:

If you don't already have asdf installed then you can install it by:

1. homebrew install asdf
2. Update your ~/.zshrc to include . $HOME/.asdf/asdf.sh
   Then you can install Erlang/Elixir:

asdf plugin-add erlang
asdf plugin-add elixir

asdf install erlang latest
asdf install elixir latest

You can also use a specific version of Erlang/Elixir. I was using Erlang 24.0 and Elixir 1.11.4.
You'll then need to set your version of Erlang/Elixir to use locally/globally.

asdf global erlang latest
asdf global elixir latest

After that you can test things by running iex and then :observer.start()

正在执行：

brew reinstall --build-from-source wxmac

就足够了。不需要卸载/重新安装其他任何东西，也不需要编辑任何文件。
正在为brew安装的长生不老药工作，具有Erlang依赖性。