Composer "Your requirements could not be resolved to an installable set of packages" in CI
Composer explored every version combination in your composer.json and its transitive graph and found none that satisfies all constraints together. The "Problem" lines below the header name the exact packages that collide.
What this error means
composer install or update stops with "Your requirements could not be resolved to an installable set of packages" followed by one or more "Problem 1" blocks explaining the conflict.
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Root composer.json requires guzzlehttp/guzzle ^6.0 but it conflicts with
another require: symfony/http-client 6.4 requires guzzlehttp/guzzle ^7.0.Common causes
Two packages require incompatible versions of a shared dependency
One require needs guzzlehttp/guzzle ^6 while another needs ^7. No single version is in both ranges, so no installable set exists.
A root constraint is tighter than the graph allows
A hard version in your root composer.json excludes the only releases that the rest of the graph can agree on.
How to fix it
Read the Problem block and loosen or upgrade
- Read each "Problem N" line to see which two requires collide on a shared package.
- Upgrade the package that pins the older range, or widen your root constraint to overlap both.
- Run the resolver again to confirm a set now exists.
composer require guzzlehttp/guzzle:^7.0 --with-all-dependenciesResolve once locally and commit the lock
Solve the graph on your machine and commit composer.lock so CI installs the resolved set instead of re-solving.
composer update
git add composer.json composer.lockHow to prevent it
- Commit
composer.lockso CI installs a known-good set instead of re-solving. - Prefer caret ranges over hard pins in your root requires.
- Upgrade related packages together so shared dependencies stay compatible.