PHP Composer

Read the Composer 2.0 announcement first for the highlights!

Complete 2.0 Changelog

• Breaking: This is a major release and while we tried to keep things compatible for most users, you might want to have a look at the UPGRADE guides
• Many CPU and memory performance improvements
• The update command is now much more deterministic as it does not take the already installed packages into account
• Package installation now performs all network operations first before doing any changes on disk, to reduce the chances of ending up with a partially updated vendor dir
• Partial updates and require/remove are now much faster as they only load the metadata required for the updated packages
• Added a platform-check step when vendor/autoload.php gets initialized which checks the current PHP version/extensions match what is expected and fails hard otherwise. Can be disabled with the platform-check config option
• Added a Composer\InstalledVersions class which is autoloaded in every project and lets you check which packages/versions are present at runtime
• Added a composer-runtime-api virtual package which you can require (as e.g. ^2.0) to ensure things like the InstalledVersions class above are present. It will effectively force people to use Composer 2.x to install your project
• Added support for parallel downloads of package metadata and zip files, this requires that the curl extension is present and we thus strongly recommend enabling curl
• Added parallel installation of packages (requires OSX/Linux/WSL, and that unzip is present in PATH)
• Added much clearer dependency resolution error reporting for common error cases
• Added support for updating to a specific version with partial updates, as well as a --with flag to pass in temporary constraint overrides
• Added automatic removal of packages which are not required anymore whenever an update is done, this will purge packages previously left over by partial updates and require/remove
• Added support for TTY mode on Linux/OSX/WSL so that script handlers now run in interactive mode
• Added only, exclude and canonical options to all repositories, see repository priorities for details
• Added support for many new lib-* packages in the platform repository and improved version detection for some ext-* and lib-* packages
• Added pre-operations-exec event to be fired before the packages get installed/upgraded/removed
• Added pre-pool-create event to be fired before the package pool for the dependency solver is created, which lets you modify the list of packages going in
• Added post-file-download event to be fired after package dist files are downloaded, which lets you do additional checks on the files
• Added --locked flag to show command to see the packages from the composer.lock file
• Added --unused flag to remove command to make sure any packages which are not needed anymore get removed
• Added --dry-run flag to require and remove commands
• Added --no-install flag to update, require and remove commands to disable the install step and only do the update step (composer.lock file update)
• Added an --ask flag to create-project command to make Composer prompt for the install dir name, useful for project install instructions
• Added support for multiple --repository flags being passed into the create-project command, only useful in combination with --add-repository to persist them to composer.json
• Added --with-dependencies and --with-all-dependencies flag aliases to require and remove commands for consistency with update
• Added shorthand aliases -w for --with-dependencies and -W for --with-all-dependencies on update/require/remove commands
• Added more info to vendor/composer/installed.json, a dev key stores whether dev requirements were installed, and every package now has an install-path key with its install location
• Added COMPOSER_DISABLE_NETWORK which if set makes Composer do its best to run offline. This can be useful when you have poor connectivity or to do benchmarking without network jitter
• Added COMPOSER_DEBUG_EVENTS=1 env var support for plugin authors to figure out which events are triggered when
• Added setCustomCacheKey to PreFileDownloadEvent and fixed a cache bug for integrations changing the processed url of package archives
• Added Composer\Util\SyncHelper for plugin authors to deal with async Promises more easily
• Added $composer->getLoop()->getHttpDownloader() to get access to the main HttpDownloader instance in plugins
• Added --json and --merge flags to config command to allow editing complex extra.* values by using json as input
• Added confirmation prompt when running Composer as superuser in interactive mode
• Added --no-check-version to validate command to remove the warning in case the version is defined
• Added --ignore-platform-req (without s) to all commands supporting --ignore-platform-reqs, which accepts a package name so you can ignore only specific platform requirements
• Added --no-dev support to show and outdated commands to skip dev requirements
• Added --format=summary flag to license command
• Added a cache-read-only config option to make the cache usable in read only mode for containers and such
• Added support for wildcards (*) in classmap autoloader paths
• Added support for configuring GitLab deploy tokens in addition to private tokens, see gitlab-token
• Added support for package version guessing for require and init command to take all platform packages into account, not just php version
• Added support for tar in artifact repositories
• Added a non-zero exit code (2) and warning to remove command when a package to be removed could not be removed
• Added --apcu-autoloader-prefix (or --apcu-prefix for dump-autoload command) flag to let people use apcu autoloading in a deterministic output way if that is needed
• Fixed package ordering when autoloading and especially when loading plugins, to make sure dependencies are loaded before their dependents
• Fixed suggest output being very spammy, it now is only one line long and shows more rarely
• Fixed conflict rules like e.g. >=5 from matching dev-master, as it is not normalized to 9999999-dev internally anymore
• Fixed solver bug resulting in endless loops in some cases
• Lots of minor bug fixes and improvements