DDev -upgrade from D9>D10 problem

Remove drush/drush and try again. I think that's been a common problem. This issue doesn't look much different from any of these others I am linking. In future, please search a little more.

Also, it is very helpful to share the original composer.json file when asking for Composer support.

Thans Cilefen for info.
I repeate the upgrade procedure once again. Removed drush before composer iupdate --dry-run.
I am getting the error:

  Problem 1
    - zendframework/zend-feed[dev-master, dev-develop, 2.11.0, ..., 2.13.x-dev] require php ^5.6 || ^7.0 -> your php version (8.1.26) does not satisfy that requirement.
    - laminas/laminas-feed[2.12.0, ..., 2.12.x-dev] require php ^5.6 || ^7.0 -> your php version (8.1.26) does not satisfy that requirement.
    - symfony/psr-http-message-bridge[v1.1.0, ..., 1.1.x-dev] require php ^5.3.3 || ^7.0 -> your php version (8.1.26) does not satisfy that requirement.
    - symfony-cmf/routing[1.4.0-RC1, ..., 1.4.x-dev] require php ^5.3.9|^7.0 -> your php version (8.1.26) does not satisfy that requirement.
    - symfony/psr-http-message-bridge[v1.2.0, ..., v1.3.0] require php ^7.1 -> your php version (8.1.26) does not satisfy that requirement.
    - laminas/laminas-feed[2.13.0, ..., 2.14.x-dev] require php ^7.3 || ~8.0.0 -> your php version (8.1.26) does not satisfy that requirement.
    - drupal/core[8.9.11, ..., 8.9.x-dev] require php ^7.0.8 -> your php version (8.1.26) does not satisfy that requirement.
    - drupal/core[9.0.10, ..., 9.0.x-dev] require php ^7.3 -> your php version (8.1.26) does not satisfy that requirement.
    - Root composer.json requires drupal/components ^2.4 -> satisfiable by drupal/components[2.4.0, 2.x-dev].
    - drupal/core-recommended 10.0.0-alpha3 requires drupal/core 10.0.0-alpha3 -> satisfiable by drupal/core[10.0.0-alpha3].
    - Conclusion: don't install drupal/core 10.0.0-alpha3 (conflict analysis result)

Here is my composer.json file:

{
    "name": "drupal-composer/drupal-project",
    "description": "Project template for Drupal 8 projects with composer",
    "type": "project",
    "license": "GPL-2.0-or-later",
    "authors": [
        {
            "name": "",
            "role": ""
        }
    ],
    "repositories": [
        {
            "type": "composer",
            "url": "https://packages.drupal.org/8"
        }
    ],
    "require": {
        "php": ">=7.0.8",
        "cweagans/composer-patches": "^1.7",
        "drupal/components": "^2.4",
        "drupal/core-composer-scaffold": "^10",
        "drupal/core-dev": "^10",
        "drupal/core-project-message": "^10",
        "drupal/core-recommended": "^10",
        "drupal/fontawesome": "^2.15",
        "drupal/honeypot": "^2.0.2",
        "drupal/radix": "^4.10",
        "drupal/smtp": "^1.2",
        "drupal/views_bootstrap": "^4.2",
        "drupal/webform": "^6.0",
        "vlucas/phpdotenv": "^4.0",
        "webflo/drupal-finder": "^1.0.0",
        "zaporylie/composer-drupal-optimizations": "^1.0"
    },
    "conflict": {
        "drupal/drupal": "*"
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "config": {
        "sort-packages": true,
        "allow-plugins": {
            "composer/installers": true,
            "dealerdirect/phpcodesniffer-composer-installer": true,
            "drupal/console-extend-plugin": true,
            "cweagans/composer-patches": true,
            "drupal/core-composer-scaffold": true,
            "drupal/core-project-message": true,
            "zaporylie/composer-drupal-optimizations": true
        }
    },
    "autoload": {
        "classmap": [
            "scripts/composer/ScriptHandler.php"
        ],
        "files": ["load.environment.php"]
    },
    "scripts": {
        "pre-install-cmd": [
            "DrupalProject\\composer\\ScriptHandler::checkComposerVersion"
        ],
        "pre-update-cmd": [
            "DrupalProject\\composer\\ScriptHandler::checkComposerVersion"
        ],
        "post-install-cmd": [
            "DrupalProject\\composer\\ScriptHandler::createRequiredFiles"
        ],
        "post-update-cmd": [
            "DrupalProject\\composer\\ScriptHandler::createRequiredFiles"
        ]
    },
    "extra": {
        "composer-exit-on-patch-failure": true,
        "patchLevel": {
            "drupal/core": "-p2"
        },
        "drupal-scaffold": {
            "locations": {
                "web-root": "web/"
            }
        },
        "installer-paths": {
            "web/core": ["type:drupal-core"],
            "web/libraries/{$name}": ["type:drupal-library"],
            "web/modules/contrib/{$name}": ["type:drupal-module"],
            "web/profiles/contrib/{$name}": ["type:drupal-profile"],
            "web/themes/contrib/{$name}": ["type:drupal-theme"],
            "drush/Commands/contrib/{$name}": ["type:drupal-drush"]
        }
    }
}

Update:
Removed drupal:components:2.4
Succesfully created:

1. composer update dry-run
2. composer update
3. composer install

In my website got error:
Fatal error: Uncaught Error: Undefined constant Symfony\Component\HttpFoundation\Request::HEADER_X_FORWARDED_ALL in /var/www/html/web/sites/default/settings.php:380 Stack trace: #0 /var/www/html/vendor/drupal/core/lib/Drupal/Core/Site/Settings.php(146): require() #1 /var/www/html/web/core/includes/install.core.inc(335): Drupal\Core\Site\Settings::initialize('/var/www/html/w...', 'sites/default', Object(Composer\Autoload\ClassLoader)) #2 /var/www/html/web/core/includes/install.core.inc(116): install_begin_request(Object(Composer\Autoload\ClassLoader), Array) #3 /var/www/html/web/core/install.php(48): install_drupal(Object(Composer\Autoload\ClassLoader)) #4 {main} thrown in /var/www/html/web/sites/default/settings.php on line 380

I have no idea about the "Undefined constant" error ...

But I also found Component was the blocker, so I am posting the method, in case it helps anyone else.

I wonder how Upgrade Status could return 100%, since components 8.x-2.4 → only "Works with Drupal: ^8.7.7 || ^9" ...

Composer returns a huge list of versions and projects in these update errors. I have come to realize that the blocker is usually a module, but spotting the module is like finding a needle in a haystack ...

Here's a one-liner, which isolates the Composer project names mentioned in the update error. When you exclude the two Drupal core modules, you have the most likely offender, almost like Sherlock Holmes :)

$ cat update-error.txt | grep -E -o "drupal/[-_\.a-z0-9]+" | sort | uniq
drupal/components
drupal/core
drupal/core-recommended

Like you found out, after removing drupal/components, the installation completes.

For the constant error in #4 see https://www.drupal.org/node/3195579 →