终极解决方案步骤

# 1. 清理旧依赖（强制模式）
rm -rf vendor composer.lock

# 2. 修正后的 composer.json（精确到每个版本）
{
    "require": {
        "php": "^7.2|^8.0",
        "alibabacloud/sdk": "1.8.958",
        "alibabacloud/dysmsapi-20170525": "1.0.8",
        "laravel/framework": "6.20.44",
        "laravel/tinker": "1.7.3",
        "prettus/l5-repository": "2.9.0",
        "guzzlehttp/guzzle": "6.5.8",
        "predis/predis": "1.1.10",
        "fideloper/proxy": "4.0.0"
    },
    "require-dev": {
        "phpunit/phpunit": "9.5.28",
        "mockery/mockery": "1.5.1",
        "nunomaduro/collision": "3.2.1",
        "fzaninotto/faker": "1.9.2",
        "beyondcode/laravel-dump-server": "1.7.0"
    }
}

精准安装命令（逐条执行）

# 清理缓存（MacOS专用路径）
rm -rf ~/Library/Caches/composer

# 分步安装核心依赖
composer require "laravel/framework:6.20.44" \
    "alibabacloud/sdk:1.8.958" \
    "alibabacloud/dysmsapi-20170525:1.0.8" \
    --no-update --ignore-platform-reqs

# 安装开发依赖（关键顺序）
composer require "phpunit/phpunit:9.5.28" \
    "mockery/mockery:1.5.1" \
    --dev --no-update --ignore-platform-reqs

# 最终强制更新
COMPOSER_MEMORY_LIMIT=-1 composer update -W --ignore-platform-reqs

关键验证点

1. 检查 PHPUnit 版本

./vendor/bin/phpunit --version
# 必须显示：PHPUnit 9.5.28

composer show phpunit/phpunit
# 必须显示：versions : 9.5.28

1. 验证 Laravel 核心版本

bash

php artisan --version
# 必须显示：Laravel Framework 6.20.44

兼容性强制锁定方案

如果仍遇到依赖冲突，使用此终极命令：

composer require \
    "laravel/framework:6.20.44" \
    "phpunit/phpunit:9.5.28" \
    "alibabacloud/sdk:1.8.958" \
    "alibabacloud/dysmsapi-20170525:1.0.8" \
    "mockery/mockery:1.5.1" \
    "guzzlehttp/guzzle:6.5.8" \
    --no-update -W --ignore-platform-reqs