The Elixir LS extension automatically runs dialyzer but fails with an error message that begins
[Error - 2:25:52 PM] Dialyzer PLT build process exited with reason:
{{:nocatch, {:dialyzer_error,
' The PLT file /home/livebook/.mix/elixir-ls-24.3.4.2_elixir-1.14.2 is not writable'}}
It appears that the MIX_HOME is not writable in the docker image. I have tried setting the output directory using the DIALYZER_PLT env variable, and also the dialyzer key :plt_core_path in the mix.exs. These attempts are not working probably because they’re meant for mix dialyzer run from the terminal.
I can’t find any documentation for how to set this output drectory for elixir-ls.
Does anyone know the answer to this? I imagine developing in the Livebook docker image is going to be more common going forward.
My guess would be, the dializer process is run as the UID:GUID user, configured in de dockerfile. And the initial user used to create the .mix folder is another one (possibly root).
This would turn this into a Unix filepermission problem ( quite common to run into when dealing with docker images)
My (quick) suggestion is to run chmod -R go+rw $MIX_HOME inside the container with root privileges.
A couple of ways to do this come to mind:
if sudo is installed you can actually do this from a livebook.
using docker (manually) start container, exec into container, run command, exit out of container, docker commit to persist the layer, docker tag to make it yours.
using Dockerfile, use FROM current image, and RUN above command, use docker build to make your own image. ( upstream might be willing to add the command to the image)
while container is running, use docker exec to enter into it as root… then run the chown.
