When using Laradock, by accessing the container Workspace I have sometimes received the following error when trying to execute PHP composer:

COMPOSER_AUTH" does not match the expected JSON schema, this may result in errors and should be resolved:  
   - Boolean value found, but an object is required

According to this issueof Laradock project, the problem has being solves, but if you still come across it, there is a simple way to get around until you update your containers.

The steps to solve it are:

  1. Access the Container Workspace Command Line
  2. Export the COMPOSER_AUTH environment variable
  3. Run the composer Command

Follow an example:

docker-compose exec --user=laradock workspace bash
export COMPOSER_AUTH=
composer update

Just as demonstrated in the second line, the COMPOSER_AUTH variable must be explicitly empty.

Conclusions

This technological work around temporary solves the problem and allows you to continue your work on the development of your project.