Composer 问题：“您的要求无法解决为一组可安装的软件包”

Question

我已经安装了 composer 1.9.0。 然后，当我运行“composer global require laravel/installer”时，出现错误“您的需求无法解析为可安装的软件包集。”

您的要求无法解决为一组可安装的软件包。

Problem 1
    - Installation request for laravel/installer ^2.2 -> satisfiable by laravel/installer[v2.2.0].
    - laravel/installer v2.2.0 requires ext-zip * -> the requested PHP extension zip is missing from your system.

To enable extensions, verify that they are enabled in your .ini files:
- /etc/php/7.2/cli/php.ini
- /etc/php/7.2/cli/conf.d/10-opcache.ini
- /etc/php/7.2/cli/conf.d/10-pdo.ini
- /etc/php/7.2/cli/conf.d/20-calendar.ini
- /etc/php/7.2/cli/conf.d/20-ctype.ini
- /etc/php/7.2/cli/conf.d/20-exif.ini
- /etc/php/7.2/cli/conf.d/20-fileinfo.ini
- /etc/php/7.2/cli/conf.d/20-ftp.ini
- /etc/php/7.2/cli/conf.d/20-gettext.ini
- /etc/php/7.2/cli/conf.d/20-iconv.ini
- /etc/php/7.2/cli/conf.d/20-json.ini
- /etc/php/7.2/cli/conf.d/20-phar.ini
- /etc/php/7.2/cli/conf.d/20-posix.ini
- /etc/php/7.2/cli/conf.d/20-readline.ini
- /etc/php/7.2/cli/conf.d/20-shmop.ini
- /etc/php/7.2/cli/conf.d/20-sockets.ini
- /etc/php/7.2/cli/conf.d/20-sysvmsg.ini
- /etc/php/7.2/cli/conf.d/20-sysvsem.ini
- /etc/php/7.2/cli/conf.d/20-sysvshm.ini
- /etc/php/7.2/cli/conf.d/20-tokenizer.ini
You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.

安装失败，正在删除。/composer.json。

Answer 1

您必须指定通常与当前框架兼容的版本。 示例：

    composer global require laravel/installer ~1.2