Problem/Motivation
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Root composer.json requires drupal/core-recommended 10.4.0 -> satisfiable by drupal/core-recommended[10.4.0].
- drupal/core-recommended 10.4.0 requires guzzlehttp/guzzle ~7.9.2 -> found guzzlehttp/guzzle[7.9.2] but these were not loaded, likely because it conflicts with another require.
Steps to reproduce
1. install drupal core 10.3.10
2. upgrade it to 10.4.0 with composer:
composer require drupal/core-recommended:10.4.0 drupal/core-composer-scaffold:10.4.0 drupal/core-project-message:10.4.0 --update-with-all-dependencies
upgrade failed with the above error