降低composer版本（亲测可行）

1.如果想把composer从2版本降到1版本

composer self-update 1.4.1

2、如果想降到1版本

composer self-update --1

3.测试

降低版本前&＃xff1a;因我原来安装PHP7.3&＃xff0c;composer  version 2.3.5

降低后&＃xff1a;php降低为5.5后&＃xff0c;报错&＃xff0c;大致意思是composer 2.3以后停止对低于php7.2.5的支持&＃xff0c;需要降低composer 版本到2.2

Composer 2.3.0 dropped support for PHP <7.2.5 and you are running 5.5.38, please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.

操作过程&＃xff1a;

注意&＃xff1a;将PHP换回7.3后执行&＃xff0c;否则还是报上面的错

composer self-update --2.2

效果图

如果想回退到composer  version 2.3.5

composer self-update --rollback

参考&＃xff1a;简介 | Composer 中文文档 | Composer 中文网