当使用apt-get update更新系统时，提示如下错误：找不到可用的公共ID
- Reading package lists... Done
- W: There is no public key available for the following key IDs:
- 9D6D8F6BC857C906
- W: There is no public key available for the following key IDs:
- 7638D0442B90D010
- W: There is no public key available for the following key IDs:
- 7638D0442B90D010
寻找了一番，找了一个解决办法。安装几个软件包，如下操作：
- apt-get install debian-keyring debian-archive-keyring
安装过程
重新更新系统
可以看到问题完美解决。
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楼主
