问无法将Laravel从5.8升级到6

EN

    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": "^7.1.3",
        "arcanedev/log-viewer": "~4.7.0",
        "davejamesmiller/laravel-breadcrumbs": "5.x",
        "devmarketer/easynav": "^1.0",
        "dompdf/dompdf": "^0.8.2",
        "fideloper/proxy": "^4.0",
        "guzzlehttp/guzzle": "^6.3",
        "intervention/image": "^2.4",
        "itsgoingd/clockwork": "^5.0",
        "kylekatarnls/laravel-carbon-2": "^1.0.0",
        "laracasts/flash": "^3.0",
        "laravel/framework": "^6.0",
        "laravel/passport": "^7.0",
        "laravel/tinker": "^1.0",
        "league/flysystem-aws-s3-v3": "~1.0",
        "maatwebsite/excel": "^3.1",
        "mpdf/mpdf": "^7.1",
        "nesbot/carbon": "2.61.0 as 1.39.0",
        "phpoffice/phpspreadsheet": "^1.2",
        "pragmarx/google2fa-laravel": "^0.2.0",
        "pusher/pusher-php-server": "~3.0",
        "robbiep/cloudconvert-laravel": "2.*",
        "santigarcor/laratrust": "5.0.*",
        "sendgrid/sendgrid": "~7",
        "symfony/css-selector": "^4.1",
        "symfony/dom-crawler": "^4.1",
        "tymon/jwt-auth": "1.0.*",
        "unsplash/unsplash": "^2.4",
        "yajra/laravel-datatables": "^1.5"
    },
    "require-dev": {
        "filp/whoops": "^2.0",
        "fzaninotto/faker": "^1.4",
        "mockery/mockery": "^1.0",
        "nunomaduro/collision": "^2.0",
        "phpunit/phpunit": "^7.0",
        "squizlabs/php_codesniffer": "^3.2"
    },
    "autoload": {
        "classmap": [
            "database/seeds",
            "database/factories"
        ],
        "psr-4": {
            "App\\": "app/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\\": "tests/"
        }
    },
    "extra": {
        "laravel": {
            "dont-discover": [
            ]
        }
    },
    "scripts": {
        "post-root-package-install": [
            "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate"
        ],
        "post-autoload-dump": [
            "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover"
        ]
    },
    "config": {
        "preferred-install": "dist",
        "sort-packages": true,
        "optimize-autoloader": true,
        "allow-plugins": {
            "kylekatarnls/update-helper": true
        }
    },
    "minimum-stability": "dev",
    "prefer-stable": true
}

Problem 1
    - Root composer.json requires laravel/framework ^6.0 -> satisfiable by laravel/framework[v6.0.0, ..., 6.x-dev].
    - arcanedev/log-viewer[4.7.0, ..., v4.7.x-dev] require arcanedev/support ~4.5.0 -> satisfiable by arcanedev/support[4.5.0].
    - arcanedev/support 4.5.0 requires illuminate/support ~5.8.0 -> satisfiable by illuminate/support[v5.8.0, ..., 5.8.x-dev].
    - Conclusion: don't install illuminate/support v5.8.36 (conflict analysis result)
    - Root composer.json requires arcanedev/log-viewer ~4.7.0 -> satisfiable by arcanedev/log-viewer[4.7.0, ..., v4.7.x-dev].