[ubuntu 18.04.2] gpg: keyserver

执行sudo apt-get update 报了

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://cli-assets.heroku.com/apt ./ InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5DC22404A6F9F1CA

把报错的公钥值放到这条命令中

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 5DC22404A6F9F1CA
gpg: key 5DC22404A6F9F1CA: public key "Heroku Inc. support@heroku.com" imported
gpg: Total number processed: 1
gpg: imported: 1
表示执行成功

再执行

sudo apt-get udpate成功