title: How to upgrade my Symfony applications while using flex?
body: <p>I found a Symfony component I would like to use in my project but it is only available since the version 5.2 and all my Symfony elements are currently in version 5.1.10.</p>
  <p>I read the following links :</p>
  <ul>
  <li><a href="https://symfony.com/doc/2.5/cookbook/upgrading.html" rel="nofollow noreferrer">How to upgrade your Symfony project</a> (but not a flex one)</li>
  <li><a href="https://symfony.com/doc/current/setup/flex.html" rel="nofollow noreferrer">How to convert your project into a flex one</a></li>
  <li>This <a href="https://github.com/symfony/flex/issues/575" rel="nofollow noreferrer">link</a> describing the same issues I'm facing but not giving a proper answer.</li>
  </ul>
  <p>But I did not found how to upgrade all my current 5.1.10 version elements to 5.2.</p>
  <p>I tried to manualy replace all '5.1.*' occurences in my <code>composer.json</code> with '5.2.*' and then run <code>composer update</code> but it did not work and throws the following error :</p>
  <pre><code>    Your requirements could not be resolved to an installable set of packages.
  Problem 1
      - The requested package symfony/symfony 5.2.* exists as symfony/symfony[5.1.x-dev, v5.1.0, v5.1.0-BETA1, v5.1.0-RC1, v5.1.0-RC2, v5.1.1, v5.1.10, v5.1.2, v5.1.3, v5.1.4, v5.1.5, v5.1.6, v5.1.7, v5.1.8, v5.1.9] but these are rejected by your constraint.
    Problem 2
      - symfony/framework-bundle v5.2.1 requires symfony/cache ^5.2 -&gt; no matching package found.
      - symfony/framework-bundle v5.2.0 requires symfony/cache ^5.2 -&gt; no matching package found.
      - Installation request for symfony/framework-bundle 5.2.* -&gt; satisfiable by symfony/framework-bundle[v5.2.0, v5.2.1].
  </code></pre>