composer: Requirements error says 'but it conflicts with another require' without saying what the problem actually is

My composer.json:

{
    "name": "drupal/git-clone-project",
    "description": "TODO",
    "type": "project",
    "license": "GPL-2.0-or-later",
    "homepage": "https://www.drupal.org/project/drupal",
    "support": {
        "docs": "https://www.drupal.org/docs/user_guide/en/index.html",
        "chat": "https://www.drupal.org/node/314178"
    },
    "repositories": [
        {
            "type": "path",
            "url": "repos/drupal",
            "options": {
                "symlink": true
            }
        },
        {
            "type": "path",
            "url": "repos/drupal/core"
        },
        {
            "type": "path",
            "url": "repos/drupal/composer/Plugin/ProjectMessage"
        },
        {
            "type": "path",
            "url": "repos/drupal/composer/Plugin/VendorHardening"
        },
        {
            "type": "composer",
            "url": "https://packages.drupal.org/8"
        }
    ],
    "require": {
        "composer/installers": "^1.9",
        "drupal/core-composer-scaffold": "^8.9",
        "drupal/drupal": "*",
        "drush/drush": "^10.3",
        "symfony/var-dumper": "^5.1"
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "config": {
        "sort-packages": true
    },
    "extra": {
        "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/{$name}": [
                "type:drupal-drush"
            ],
            "web/modules/custom/{$name}": [
                "type:drupal-custom-module"
            ],
            "web/themes/custom/{$name}": [
                "type:drupal-custom-theme"
            ]
        }
    }
}

Additionally need to do the following in the project folder before installing with Composer:

mkdir repos
cd repos
git clone --branch 9.2.x https://git.drupalcode.org/project/drupal.git

Output of composer diagnose:

Checking composer.json: WARNING
require.drupal/drupal : unbound version constraints (*) should be avoided
Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: OK
Checking https connectivity to packagist: OK
Checking github.com rate limit: OK
Checking disk free space: OK
Checking pubkeys:
Tags Public Key Fingerprint: 57815BA2 7E54DC31 7ECC7CC5 573090D0  87719BA6 8F3BB723 4E5D42D0 84A14642
Dev Public Key Fingerprint: 4AC45767 E5EC2265 2F0C1167 CBBB8A2B  0C708369 153E328C AD90147D AFE50952
OK
Checking composer version: You are not running the latest stable version, run `composer self-update` to update (2.0.3 => 2.0.4)
Composer version: 2.0.3
PHP version: 7.4.2
PHP binary path: /Applications/MAMP/bin/php/php7.4.2/bin/php
OpenSSL version: OpenSSL 1.0.2o  27 Mar 2018
cURL version: 7.65.1 libz 1.2.8 ssl OpenSSL/1.0.2o
zip extension: OK

When I run this command:

composer require -W drupal/core-dev ^9.2

I get the following output:

Running composer update drupal/core-dev --with-all-dependencies
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Root composer.json requires drupal/drupal *, found drupal/drupal[9.2.x-dev] but it conflicts with another require.

And I expected this to happen:

I need to be told what the ‘another require’ actually is, otherwise I can’t understand or fix the problem.