Cannot start observer on macOS

Erlang & BEAM Forum (archived) Questions / Help (archived)
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Hello.
I am following the OTP and Mix tutorial and I got to the step where I need to start the observer using :observer.start. I am currently getting the following error:

Could not find 'wxe_driver.so' in: /Users/valio/.asdf/installs/erlang/23.2.1/lib/wx-1.9.2/priv

I have followed the instruction for installing erlang via asdf:

  1. Install wxmac using brew
  2. Install erlang using asdf

Still getting the error.
During the build process for erlang I see:

APPLICATIONS INFORMATION (See: /Users/valio/.asdf/plugins/erlang/kerl-home/builds/asdf_23.2.1/otp_build_23.2.1.log)
 * wx             : No OpenGL headers found, wx will NOT be usable
 * No GLU headers (glu.h) found, wx will NOT be usable

I am not sure if this is relevant.
I have tried reinstalling everything multiple times with no success.

Please help!

2

When installing erlang with asdf, which uses kerl under the hood, you will want to set some environment variables in your shells profile (example: .bash_profile) so that the installation can find programs like wx-config. Here is what I have set in my .bash_profile

export JAVAC="/usr/bin/javac"
export WX_CONFIG="/usr/local/bin/wx-config"
export KERL_CONFIGURE_OPTIONS="--with-javac=$JAVAC --with-wx-config=$WX_CONFIG"

To find the paths of javac and wx-config you can type which javac and which wx-config in your terminal. After setting these in your shell, reinstall erlang. Observer needs wx widgets because it is a graphical interface. With erlang installed knowing where to find wx-config, observer should work.

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4

Hi Logan. Unfortunately that didn’t work for some reason.
Here is what I did:

  1. uninstalled erlang using asdf uninstall erlang 23.2.1
  2. Checked the paths to javac and wx-config
  3. Added the variables to my shell
  4. Installed erlang using asdf install erlang latest
  5. I then run iex -S mix inside my project folder and try to run :observer.start

I get the same error.

In the build logs for erlang I see:

checking for debug build of wxWidgets... checking for wx-config... /usr/local/bin/wx-config
checking for wxWidgets version >= 2.8.4 (--unicode --debug=yes)... yes (version 3.0.5)
checking for wxWidgets static library... no
checking for standard build of wxWidgets... checking for wx-config... /usr/local/bin/wx-config
checking for wxWidgets version >= 2.8.4 (--unicode --debug=no)... yes (version 3.0.5)
checking for wxWidgets static library... no

Also, I have force uninstalled the erlang the comes with elixir when it is installed using brew.

5

I am on Elixir 1.11.3-otp-23 and Erlang 23.2.1, I have wxmac installed (at 3.0.5.1_1) and I don’t have to use any variables to have :observer.start() working.

Are you on the latest macOS? Did you do xcode-select --install after your last macOS upgrade?

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6

I faced a problem with the Mac OSx Big Sur.
And these were the steps I successfully set up!
I uninstall the wxmac:

brew uninstall wxmac

and reinstalled to build wxmac locally instead of installing already built binary using the extra flag:

brew install --build-from-source wxmac

Update the plugin erlang for asdf:

asdf plugin-update erlang

skip the java dependency during installation use:
export KERL_CONFIGURE_OPTIONS="--disable-debug --without-javac"

and then install the last version of the Erlang:

asdf install erlang latest

and now when I try to run the :observer.start() it works!

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