wget -qO - https://www.mongodb.org/static/pgp/server-5.0.asc | sudo apt-key add -
当我运行上面的命令导入MongoDB公共GPG密钥时，我得到了这个错误。MongoDB文档中有类似的安装步骤。如何通过PPA安装MongoDB的最新版本？
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
gpg: invalid key resource URL '/tmp/apt-key-
gpghome.y7PLc7iFDy/home:manuelschneid3r.asc.gpg'
gpg: keyblock resource '(null)': General error
gpg: key 7721F63BD38B4796: 2 signatures not checked due to missing keys
gpg: key 8C718D3B5072E1F5: 75 signatures not checked due to missing keys
gpg: key 7721F63BD38B4796: 2 signatures not checked due to missing keys
gpg: key 1488EB46E192A257: 1 signature not checked due to a missing key
gpg: key 1488EB46E192A257: 1 signature not checked due to a missing key
gpg: key D94AA3F0EFE21092: 3 signatures not checked due to missing keys
gpg: key 871920D1991BC93C: 1 signature not checked due to a missing key
gpg: Total number processed: 17
gpg: skipped new keys: 17
你能试试下面的吗？两个人在安装MongoDB时遇到了与您类似的问题，他们解决了删除gpg密钥的问题。
sudo rm /etc/apt/trusted.gpg.d/home:manuelschneid3r.gpg
来源：askubuntu.com