composer/composer · error · InvalidArgumentException

Could not find package "{needle}" in your project

Error message

Could not find package "{needle}" in your project

What it means

Thrown by BaseDependencyCommand (why/why-not) when findPackagesWithReplacersAndProviders() returns no packages matching the requested needle in the installed/locked repositories. The needle (first argument) must correspond to an installed package or one that is provided/replaced by an installed package. It signals the dependency is not present in the project.

Source

Thrown at src/Composer/Command/BaseDependencyCommand.php:102

                return 1;
            }

            $repos[] = $localRepo;

            $platformOverrides = $composer->getConfig()->get('platform') ?: [];
            $repos[] = new PlatformRepository([], $platformOverrides);
        }

        $installedRepo = new InstalledRepository($repos);

        // Parse package name and constraint
        $needle = $input->getArgument(self::ARGUMENT_PACKAGE);
        $textConstraint = $input->hasArgument(self::ARGUMENT_CONSTRAINT) ? $input->getArgument(self::ARGUMENT_CONSTRAINT) : '*';

        // Find packages that are or provide the requested package first
        $packages = $installedRepo->findPackagesWithReplacersAndProviders($needle);
        if (empty($packages)) {
            throw new \InvalidArgumentException(sprintf('Could not find package "%s" in your project', $needle));
        }

        // If the version we ask for is not installed then we need to locate it in remote repos and add it.
        // This is needed for why-not to resolve conflicts from an uninstalled version against installed packages.
        $matchedPackage = $installedRepo->findPackage($needle, $textConstraint);
        if (!$matchedPackage) {
            $defaultRepos = new CompositeRepository(RepositoryFactory::defaultRepos($this->getIO(), $composer->getConfig(), $composer->getRepositoryManager()));
            if ($match = $defaultRepos->findPackage($needle, $textConstraint)) {
                $installedRepo->addRepository(new InstalledArrayRepository([clone $match]));
            } elseif (PlatformRepository::isPlatformPackage($needle)) {
                $parser = new VersionParser();
                $constraint = $parser->parseConstraints($textConstraint);
                if ($constraint->getLowerBound() !== Bound::zero()) {
                    $tempPlatformPkg = new Package($needle, $constraint->getLowerBound()->getVersion(), $constraint->getLowerBound()->getVersion());
                    $installedRepo->addRepository(new InstalledArrayRepository([$tempPlatformPkg]));
                }
            } else {
                $this->getIO()->writeError('<error>Package "'.$needle.'" could not be found with constraint "'.$textConstraint.'", results below will most likely be incomplete.</error>');

View on GitHub (pinned to c435d285c9)

Solutions

1. Verify the exact package name with `composer show` (lists installed packages) or `composer show --installed`.
2. If the package is provided/replaced under another name, query that name instead.
3. Run `composer install`/`composer update` so the package is present in the local repo.
4. Check for typos against the package's canonical vendor/name on packagist.org.

Example fix

// before
composer why monolog
// after
composer why monolog/monolog

// Confirm the package is installed before running why/why-not:
exec('composer show --installed 2>&1', $out, $code);
if ($code !== 0 || !preg_grep('/^' . preg_quote($needle, '/') . '\s/', $out)) {
    fwrite(STDERR, "$needle is not installed in this project\n");
    exit(1);
}

When it happens

Trigger: Running `composer why nonexistent/pkg`, misspelling a package name (`composer why monolog`), or querying a package that exists in the lock but under a different name (e.g. a provide/replace alias).

Common situations: Typo in package name, querying a transitive dependency by the wrong name, or running why before install so the package isn't in the installed repos. The message says "in your project" because it only searches local/locked repos, not all of packagist.

Related errors

• A valid composer.lock file is required to run this command w
• Package "${name}" is installed but not a direct dependent of
• Not enough arguments (missing: "packages").
• Invalid working directory specified, {workingDir} does not e
• --abandoned must be one of {values}.

AI-assisted analysis of composer/composer@c435d285c9 (2026-08-07). Data as JSON: /api/errors/bfdeacf8fae96e06. Report an issue: GitHub.