The serializer cannot be installed in a Laravel version 10 project. about serializer HOT 2 CLOSED

If you use the --with-all-dependencies flag as the Composer message suggests, unless you've got a package that ONLY supports doctrine/lexer:>=3.0, you should be able to install the serializer and have the lexer package downgraded to 2.x.

Checking a Laravel project I have at work:

$ composer why doctrine/lexer
doctrine/annotations      2.0.1   requires doctrine/lexer (^2 || ^3)     
egulias/email-validator   4.0.1   requires doctrine/lexer (^2.0 || ^3.0) 
friendsofphp/php-cs-fixer v3.16.0 requires doctrine/lexer (^2 || ^3)

So, Laravel itself does NOT depend on the lexer.

Note, because of the lexer package's API redesign, either a combination of 1.x and 2.x or a combination of 2.x and 3.x can be supported, there isn't a sane way to support all 3 major versions.

from serializer.

Thank you very much for your quick reply. As you correctly described, the installation works with the --with-all-dependencies flag. Nevertheless, I thought I would create this ticket to point out that Laravel 10 no longer supports doctrine-lexer version 1 and the message appears when adding the JMS/Serializer in a newly deployed Laravel app.

from serializer.