composer install错误的解决办法：首先打开终端命令窗口；然后通过“rm -f composer.lock”命令删除“composer.lock”；最后执行“composer install”命令即可。
composer install错误怎么办？
执行composer install 报错的解决办法
执行composer install后报以下错误：
Loading composer repositories with package information Installing dependencies (including require-dev) from lock file Your requirements could not be resolved to an installable set of packages. Problem 1 - laravel/horizon v1.4.3 requires ext-pcntl * -> the requested PHP extension pcntl is missing from your system. - laravel/horizon v1.4.3 requires ext-pcntl * -> the requested PHP extension pcntl is missing from your system. - Installation request for laravel/horizon v1.4.3 -> satisfiable by laravel/horizon[v1.4.3].
解决办法：
rm -f composer.lock
再次执行composer install
