A fatal error occurs when installing Composer dependencies with Drush | Acquia Product Documentation
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A fatal error occurs when installing Composer dependencies with Drush
A fatal error occurs when installing Composer dependencies with Drush
Date Published: April 3, 2025
Composer Manager depends on the Composer Drush extension to install the Composer tool.
Possible cause: Outdated Composer
If you run drush composer-manager commands and see errors like the following, try updating your Composer Drush extension.
[RuntimeException]
Could not load package...
[UnexpectedValueException]
Could not parse version constraint...
To resolve this issue, delete the current version of the Composer Drush extension and reinstall it by running the following commands ( 8.x is the correct version):
rm -Rf ~/.drush/composer
drush dl composer-8.x
Then run the following command inside of your Drupal installation: