Argon2_elixir and versions 1 and 2 of bcrypt_elixir use dirty schedulers. When deploying either of these, make sure that you provision more than one core. Otherwise the the dirty schedulers will not work.

In order to use argon2_elixir or bcrypt_elixir in Docker, you will probably need to manually compile it in your Dockerfile. In order to do this on the Alpine image, you are going to need make, gcc and libc-dev. Add the following lines to your Dockerfile, right after RUN mix deps.get

RUN apk add --no-cache make gcc libc-dev

Also, remember to add your local _build and deps folders to .dockerignore.

If you are using Vagrant, you might need to add the following line to your Vagrantfile:

config.vm.synced_folder ".", "/vagrant", type: "rsync", rsync__exclude: ["_build", "deps"]