curl error 56 during composer install

We have have recently upgraded Magento from 2.3.5 to 2.4.4 and trying do deploy the update to our staging server. During the composer install we get the following error after a while:

$ php8.1 /usr/local/bin/composer install [...] - Installing techdivision/import-product-bundle (25.0.0): Extracting archive - Installing techdivision/import-product-bundle-ee (27.0.0): Extracting archive - Installing techdivision/import-customer (17.0.1): Extracting archive - Installing techdivision/import-customer-address (17.0.1): Extracting archive - Installing techdivision/import-converter (11.0.0): Extracting archive https://repo.packagist.org could not be fully loaded (curl error 56 while downloading https://repo.packagist.org/p2/techdivision/import-category.json: Unexpected EOF), package information was loaded from the local cache and may be out of date Install of sebastian/version failed Install of sebastian/type failed Install of sebastian/resource-operations failed Install of sebastian/recursion-context failed Install of sebastian/object-reflector failed [...] In CurlDownloader.php line 358: curl error 56 while downloading https://repo.packagist.org/p2/techdivision/import-category.json: Unexpected EOF 

When I open the link, the file does not have any errors. Trying the composer install again it will succeed with this file but fail again at the next. Further repeating the step just brings us seemingly one module further. Until now it always fails at the same module shown above.

OS: Ubuntu 18.04.6 LTS
PHP Version: 8.1.9
Composer Version: 2.4.1 2022-08-20 11:44:50
cURL Information: 7.58.0

The verbose output of the error is:

$ php8.1 /usr/local/bin/composer install -vvv [...] > pre-package-update: Laminas\DependencyPlugin\DependencyRewriterPluginDelegator->onPrePackageInstallOrUpdate In Laminas\DependencyPlugin\DependencyRewriterV2::onPrePackageInstallOrUpdate Exiting; package "techdivision/import-category" does not have a replacement > pre-package-update: Magento\ComposerDependencyVersionAuditPlugin\Plugin->packageUpdate Downloading https://repo.packagist.org/p2/techdivision/import-category.json Reading /home/www-data/.composer/cache/repo/https---repo.packagist.org/provider-techdivision~import-category~dev.json from cache Downloading https://repo.packagist.org/p2/techdivision/import-category~dev.json if modified https://repo.packagist.org could not be fully loaded (curl error 56 while downloading https://repo.packagist.org/p2/techdivision/import-category.json: Unexpected EOF), package information was loaded from the local cache and may be out of date [304] https://repo.packagist.org/p2/techdivision/import-category~dev.json [...] In CurlDownloader.php line 358: [Composer\Downloader\TransportException] curl error 56 while downloading https://repo.packagist.org/p2/techdivision/import-category.json: Unexpected EOF Exception trace: at phar:///usr/local/bin/composer2/src/Composer/Util/Http/CurlDownloader.php:358 Composer\Util\Http\CurlDownloader->tick() at phar:///usr/local/bin/composer2/src/Composer/Util/HttpDownloader.php:371 Composer\Util\HttpDownloader->countActiveJobs() at phar:///usr/local/bin/composer2/src/Composer/Util/Loop.php:89 Composer\Util\Loop->wait() at phar:///usr/local/bin/composer2/src/Composer/Repository/ComposerRepository.php:1058 Composer\Repository\ComposerRepository->loadAsyncPackages() at phar:///usr/local/bin/composer2/src/Composer/Repository/ComposerRepository.php:531 Composer\Repository\ComposerRepository->loadPackages() at phar:///usr/local/bin/composer2/src/Composer/Repository/RepositorySet.php:197 Composer\Repository\RepositorySet->findPackages() at phar:///usr/local/bin/composer2/src/Composer/Package/Version/VersionSelector.php:85 Composer\Package\Version\VersionSelector->findBestCandidate() at /var/www/html/magento2/web/vendor/magento/composer-dependency-version-audit-plugin/src/Utils/Version.php:90 Magento\ComposerDependencyVersionAuditPlugin\Utils\Version->findBestCandidateComposer2() at /var/www/html/magento2/web/vendor/magento/composer-dependency-version-audit-plugin/src/Utils/Version.php:40 Magento\ComposerDependencyVersionAuditPlugin\Utils\Version->findBestCandidate() at /var/www/html/magento2/web/vendor/magento/composer-dependency-version-audit-plugin/src/Plugin.php:139 Magento\ComposerDependencyVersionAuditPlugin\Plugin->packageUpdate() at phar:///usr/local/bin/composer2/src/Composer/EventDispatcher/EventDispatcher.php:200 Composer\EventDispatcher\EventDispatcher->doDispatch() at phar:///usr/local/bin/composer2/src/Composer/EventDispatcher/EventDispatcher.php:142 Composer\EventDispatcher\EventDispatcher->dispatchPackageEvent() at phar:///usr/local/bin/composer2/src/Composer/Installer/InstallationManager.php:380 Composer\Installer\InstallationManager->executeBatch() at phar:///usr/local/bin/composer2/src/Composer/Installer/InstallationManager.php:334 Composer\Installer\InstallationManager->downloadAndExecuteBatch() at phar:///usr/local/bin/composer2/src/Composer/Installer/InstallationManager.php:242 Composer\Installer\InstallationManager->execute() at phar:///usr/local/bin/composer2/src/Composer/Installer.php:787 Composer\Installer->doInstall() at phar:///usr/local/bin/composer2/src/Composer/Installer.php:283 Composer\Installer->run() at phar:///usr/local/bin/composer2/src/Composer/Command/InstallCommand.php:144 Composer\Command\InstallCommand->execute() at phar:///usr/local/bin/composer2/vendor/symfony/console/Command/Command.php:298 Symfony\Component\Console\Command\Command->run() at phar:///usr/local/bin/composer2/vendor/symfony/console/Application.php:1024 Symfony\Component\Console\Application->doRunCommand() at phar:///usr/local/bin/composer2/vendor/symfony/console/Application.php:299 Symfony\Component\Console\Application->doRun() at phar:///usr/local/bin/composer2/src/Composer/Console/Application.php:343 Composer\Console\Application->doRun() at phar:///usr/local/bin/composer2/vendor/symfony/console/Application.php:171 Symfony\Component\Console\Application->run() at phar:///usr/local/bin/composer2/src/Composer/Console/Application.php:138 Composer\Console\Application->run() at phar:///usr/local/bin/composer2/bin/composer:88 require() at /usr/local/bin/composer2:29 

I noticed a difference in the composer version locally and used on the server but downgrading to 2.3.5 did not help. Locally or in our docker environment we did not encounter this error before.

As per suggestion I've used curl and wget in order to verify what data I am receiving. In both cases I receive valid json and it looks completely normal:

$ curl https://repo.packagist.org/p2/techdivision/import-category.json | jsonlint-php % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 52929 0 52929 0 0 1013k 0 --:--:-- --:--:-- --:--:-- 994k Valid JSON (stdin) $ wget https://repo.packagist.org/p2/techdivision/import-category.json --2022-10-06 09:48:06-- https://repo.packagist.org/p2/techdivision/import-category.json Resolving repo.packagist.org (repo.packagist.org)... 2001:41d0:52:600::8cf, 5.196.224.108 Connecting to repo.packagist.org (repo.packagist.org)|2001:41d0:52:600::8cf|:443... connected. HTTP request sent, awaiting response... 200 OK Length: unspecified [application/json] Saving to: ‘import-category.json’ import-category.json [ <=> ] 51,69K --.-KB/s in 0,008s 2022-10-06 09:48:06 (6,50 MB/s) - ‘import-category.json’ saved [52929] $ file import-category.json import-category.json: ASCII text, with very long lines, with no line terminators $ jsonlint-php import-category.json Valid JSON (import-category.json) 

Trying to search for this error message in combination with composer did not yield any results. What could be the cause of this error?

Our current workaround is to disable php-curl.