How to Fix the Composer Error: "Your requirements could not be resolved to an installable set of packages"
Last updated on by Ashley Allen

When working on PHP projects and using Composer to manage your dependencies, you might encounter the error message "Your requirements could not be resolved to an installable set of packages."
I've encountered this error many times before, and it can be caused by a variety of reasons. The first time I saw it, I remember feeling a bit overwhelmed and not knowing where to start. So, if you feel the same way, that's totally fine! In this article, we'll break down the error and look at some common causes and solutions.
By the end of the article, you should have a better understanding of what's causing the error and how to resolve it.
Conflicts Between Dependency Versions
The most common reason I encounter this error is due to a conflict between the required versions of packages. I tend to find this when upgrading a Laravel application to the newest version of Laravel and I have some installed packages that clash with the latest version.
Let's take this example composer.json
file:
{ "name": "ashallen/composer-test", "require": { "php": "^8.4", "ashallendesign/short-url": "^7.0" }}
We can see that we're requiring PHP ^8.4 and ashallendesign/short-url
^7.0. Let's assume that the exact version of ashallendesign/short-url
we're using is v7.9.0.
Let's say we want to add nesbot/carbon ^3.0
(a fantastic library for handling dates in PHP) as a dependency on our project. Unfortunately, ashallendesign/short-url v7.9.0
only supports nesbot/carbon ^2.0
, but support for nesbot/carbon ^3.0
was added in v7.10.0.
Let's try and install nesbot/carbon ^3.0
:
composer require nesbot/carbon:^3.0
Running the above command will give you the following error:
Running Composer update nesbot/carbonLoading composer repositories with package informationUpdating dependenciesYour requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires nesbot/carbon ^3.0, found nesbot/carbon[3.0.0, ..., 3.8.2] but these were not loaded, likely because it conflicts with another require. Problem 2 - ashallendesign/short-url is locked to version v7.9.0 and an update of this package was not requested. - ashallendesign/short-url v7.9.0 requires nesbot/carbon ~2.0 -> found nesbot/carbon[2.0.0, ..., 2.72.5] but it conflicts with your root composer.json require (^3.0). Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions. Installation failed, reverting ./composer.json and ./composer.lock to their original content.
Woah! What's all this?
It can be overwhelming if this is your first time seeing this error. But it's not as bad as it seems and is actually incredibly useful. Let's break down the error message and then look at some solutions. We can then take small, logical steps to resolve the issue. You don't want to make any big decisions without understanding the full picture because you'll risk breaking your application.
The "Problem 1" section of the error message states that we're attempting to require nesbot/carbon ^3.0
and it shows us the available versions (v3.0.0 - v3.8.2). But it tells us that they can't be loaded. Although this seems obvious to us right now since we've just tried to install it, this can be useful if the error is caused by a package you're not directly requiring and you're unsure where the conflict is.
The "Problem 2" section tells us that ashallendesign/short-url
is locked to v7.9.0 and requires nesbot/carbon ~2.0
. So, we can only install versions of nesbot/carbon between v2.0.0 and v2.72.5. This is a problem because we're trying to require ^3.0.
At this stage, we have an understanding of what's causing the conflict: We want ^3.0
, but one of our dependencies needs ^2.0
.
There are several possible solutions to choose from:
1. Update Your Existing Dependency
In my opinion, the best solution, at least in this example, would be to update ashallendesign/short-url
to a version that supports nesbot/carbon ^3.0
.
As I mentioned earlier, support for nesbot/carbon ^3.0
was added in ashallendesign/short-url v7.10.0
. This means if we update to at least v7.10.0, we should be able to require nesbot/carbon ^3.0
.
You might have noticed in the error message that Composer suggested using a --with-all-dependencies
flag. This flag allows Composer to update other packages to resolve the conflict automatically. Let's run it:
composer require nesbot/carbon:^3.0 --with-all-dependencies
This would now install nesbot/carbon ^3.0
and update ashallendesign/short-url
to v7.10.0.
Remember that after updating any dependencies, you should run your tests to ensure your application still works as expected. Although PHP packages generally follow semantic versioning and have tests, there's always a chance that something could break. So, it's good to have tests in place to catch any issues.
I'd also highly recommend having some form of error monitoring in place in your production environment. This way, if something does break, you'll be notified and can fix it quickly. A fantastic tool for this is Honeybadger. It's easy to set up, has saved me a lot of time and headaches, and integrates really nicely with Laravel.
2. Use an Older Version of the New Package
Using an older version of the package may be a suitable solution if you don't need the newer version's new features. You might want to use this approach if the ashallendesign/short-url
package doesn't have a newer version that supports nesbot/carbon ^3.0
yet. However, you should be aware that this might result in missing out on new features, bug fixes, and security updates.
If you find there isn't a newer version of the package that supports the version you want to use, you could reach out to the package's maintainer and ask if they have plans to support it. You could also consider contributing to the package if you have the time and knowledge. This is a great way to give back to the community and help improve the package for everyone while also taking some pressure off the package maintainer.
To install nesbot/carbon ^2.0
to satisfy the requirements of ashallendesign/short-url v7.9.0
, you can run the following command:
composer require nesbot/carbon:^2.0
3. Remove the Existing Dependency
Typically, you won't want to remove the package you're already using. If it's installed in your project, then it likely means you're using it to provide some functionality to your app. So, removing it might cause new issues since you'll need to find a replacement (either building it yourself or using a different package).
But if you find that you're not using the package or can live without it, removing it might be a suitable solution.
Conflicts Between PHP versions
Another common reason for this error is a conflict between the required PHP version in your composer.json
file and the PHP you're using to install the packages.
For example, assume we are running PHP 8.3 on our machine and have the following composer.json
file:
Note: I've purposely kept the composer.json
file simple for this example so we can focus on the cause of the error. In a real-world application, you'd likely have more dependencies.
{ "name": "ashallen/composer-test", "require": { "php": "^8.4" }, "require-dev": { "phpunit/phpunit": "^11.5" }}
As we can see in the composer.json
file, we're requiring PHP ^8.4. But we're running PHP 8.3 on our machine. Therefore, running composer install
will give us the following error:
Loading composer repositories with package informationUpdating dependenciesYour requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php ^8.4 but your php version (8.3.14) does not satisfy that requirement.
A possible solution to fixing this error is to use the --ignore-platform-reqs
flag when running composer install
. This flag tells Composer to ignore the platform requirements and install the packages anyway.
composer install --ignore-platform-reqs
Running the above command would install the packages without checking the PHP version. However, I wouldn't typically recommend this approach since it might cause other issues later on. For example, the packages you're installing might use PHP 8.4-specific features that won't work with PHP 8.3.
In my opinion, the best way to fix this error is to update your PHP version to satisfy the required PHP version in your composer.json
file. In this case, you'd update your PHP version to 8.4.
In an ideal world, you'll want to be running the exact same PHP version in your local environment as your team and your production environment. This way, you're all working on a level playing field and less likely to run into PHP-version-related issues when deploying your application.
Summary
Hopefully, this article has given you a better understanding of why you might see the error "Your requirements could not be resolved to an installable set of packages" when using Composer.
Remember to always check the error message for more information on what's causing the issue and take logical, small steps to resolve it. Don't make any big decisions without understanding the full picture.
As I mentioned, make sure you have a test suite in place to catch any issues that might arise after updating, adding, or removing dependencies. Consider using an error monitoring tool like Honeybadger to catch issues in your production environment.
I am a freelance Laravel web developer who loves contributing to open-source projects, building exciting systems, and helping others learn about web development.