_update_dep_errors.rst.inc

Dependency Errors
~~~~~~~~~~~~~~~~~

If you get a dependency error, it may simply mean that you need to upgrade
other Symfony dependencies too. In that case, try the following command:

.. code-block:: terminal

    $ composer update symfony/symfony --with-dependencies

This updates ``symfony/symfony`` and *all* packages that it depends on, which will
include several other packages. By using tight version constraints in
``composer.json``, you can control what versions each library upgrades to.

If this still doesn't work, your ``composer.json`` file may specify a version
for a library that is not compatible with the newer Symfony version. In that
case, updating that library to a newer version in ``composer.json`` may solve
the issue.

Or, you may have deeper issues where different libraries depend on conflicting
versions of other libraries. Check your error message to debug.

Another issue that may happen is that the project dependencies can be installed
in your local computer but not on the remote server. This usually happens when
the PHP versions are different on each machine. The solution is to add the
`platform`_ config option in your `composer.json` file to define the highest
PHP version allowed for the dependencies (set it to server's PHP version).

.. _`platform`: https://getcomposer.org/doc/06-config.md#platform