I cannot activate the extension in TYPO3 v10.4 in composer mode

[someplace53]

If I do composer req fab/rss-display and then try to activate it through the ExtensionManger, I get the following error message (debug mode):

(1/1) #1519931815 UnexpectedValueException The package "rss_display" depends on "simplepie/simplepie" which is not present in the system.

As I still need to activate the extension in TYPO3 v10.4, the newest version of this extension seems not to work with TYPO3 version 10.4. My suspicion is that this is a problem with TYPO3 rather than this extension, but you could remove 10.4 version constraint (I did not test this with 11.5)

Tested in TYPO3 Version 10.4.31.

btw as a workaround you could install a lower version (5.1) and than update the extension and this seems to work quite fine, with the exception that you cannot activate or deactivate any extension anymore

[someplace53]

small addition on my part, it seems to work if you add the constraints part from the last version to the ext_emconf.php:

<?php

$EM_CONF[$_EXTKEY] = [
    'title' => 'RSS Feed Display',
    'description' => 'Fetch a RSS / Atom Feed and display its content on the Frontend.',
    'category' => 'plugin',
    'version' => '6.0.0',
    'state' => 'stable',
    'author' => 'Fabien Udriot',
    'author_email' => 'fabien@ecodev.ch',
    'author_company' => 'Ecodev',
    'constraints' => [
        'depends' => [
            'typo3' => '9.5.0-11.5.99',
        ],
        'conflicts' => [
        ],
        'suggests' => [
        ],
    ],
];

and yes I increased the version number for the constraint.

[mbrodala]

This is exactly the correct fix. Without constraints/depends the TYPO3 package manager will fall back to require from the composer.json of a package. Which in this case leads to the mentioned error.

(Source: https://github.com/TYPO3/typo3/blob/10.4/typo3/sysext/core/Classes/Package/PackageManager.php#L853L874)