composer install 出现 RuntimeException Failed to execute

报错：composer.json 的  require添加新包 需要删除composer.lock和vender 从新composer install

[RuntimeException]
Failed to execute git checkout ‘xxxx‘ -- && git reset --hard ‘xxxxx‘ --

error: unable to read sha1 file of xxxxxx (xxxx)

......

......

解决方法：

composer clear

composer install

参考：https://segmentfault.com/q/1010000018768672

原文：https://www.cnblogs.com/songyanan/p/13294282.html