composer update: Discard changes [y,n,v,d,s,?]?

composer update 出现如下错误：

Package operations: 3 installs, 26 updates, 0 removals
  - Updating nesbot/carbon (2.27.0 => 2.28.0):     The package has modified files:
    M bin/carbon
    Discard changes [y,n,v,d,s,?]?

y - discard changes and apply the update

n - abort the update and let you manually clean things up

v - view modified files d - view local modifications (diff)

s - stash changes and try to reapply them after the update

查看源码：https://github.com/composer/composer/blob/master/src/Composer/Downloader/GitDownloader.php#L269-L310

可选择 y, 然后运行 composer require nesbot/carbon --prefer-dist 重新安装。

参考：

https://www.e-learn.cn/content/wangluowenzhang/604410