在 Ubuntu 20.04 LTS 上，我正在尝试安装 MongoDB、Sublime Text 3 等软件包，但在添加它们之前，必须添加它们的 repo url。我正在尝试这个命令：
wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -
它失败了这条消息：
gpg: invalid key resource URL '/tmp/apt-key-gpghome.Mi0IvTayBR/home:hawkeye116477:waterfox.asc.gpg'
gpg: keyblock resource '(null)': General error
gpg: key 7721F63BD38B4796: 2 signatures not checked due to missing keys
gpg: key 5E62D791625A271E: 1 signature not checked due to a missing key
gpg: key 3B4FE6ACC0B21F32: 3 signatures not checked due to missing keys
gpg: key D94AA3F0EFE21092: 3 signatures not checked due to missing keys
gpg: key …