Your requirements could not be resolved to an installable set of packages.

[keuvy]

Error happening when I try to install this package.

php: 8.3.0
lumen: v10.0.2

[ridzria]

Same here as well. Tried the following as well but not successful.

->>> composer require flipbox/lumen-generator:^9.3.0
./composer.json has been updated
Running composer update flipbox/lumen-generator
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - classpreloader/classpreloader 3.0.0 requires nikic/php-parser ^1.0|^2.0 -> found nikic/php-parser[v1.0.0, ..., v1.4.1, v2.0.0, v2.0.1, v2.1.0, v2.1.1] but the package is fixed to v5.0.2 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - classpreloader/classpreloader[3.1.0, ..., 3.2.1] require nikic/php-parser ^1.0|^2.0|^3.0 -> found nikic/php-parser[v1.0.0, ..., v1.4.1, v2.0.0, v2.0.1, v2.1.0, v2.1.1, v3.0.0, ..., v3.1.5] but the package is fixed to v5.0.2 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - classpreloader/classpreloader[4.0.0, ..., 4.0.1] require php ^7.0.8 -> your php version (8.3.0) does not satisfy that requirement.
    - classpreloader/classpreloader[4.1.0, ..., 4.2.0] require nikic/php-parser ^4.10.3 -> found nikic/php-parser[v4.10.3, ..., v4.19.1] but the package is fixed to v5.0.2 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - flipbox/lumen-generator 9.3.0 requires classpreloader/classpreloader ^3.0|^4.0|^4.2 -> satisfiable by classpreloader/classpreloader[3.0.0, 3.1.0, 3.2.0, 3.2.1, 4.0.0, 4.0.1, 4.1.0, 4.2.0].
    - Root composer.json requires flipbox/lumen-generator ^9.3.0 -> satisfiable by flipbox/lumen-generator[9.3.0].

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

Installation failed, reverting ./composer.json and ./composer.lock to their original content.

php: 8.2.0
lumen: 10.0.3

[chrisvoo]

The only way to install it with latest version of lumen is composer require flipbox/lumen-generator -W which downgrades nikic/php-parser (v5.3.1 => v4.19.4). I don't know what this implicates.