su chayes
composer update drupal/core webflo/drupal-core-require-dev --with-dependencies

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composer outdated
composer outdated "drupal/*"

composer update --dry-run

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composer prohibits allows you to see exactly what is preventing a package from being updated. For example, on this codebase, I know I want to end up with drupal/core:8.5.0, so I can run:

composer prohibits drupal/core:8.5.0