当我跑步时：
sudo apt-get update
我收到以下错误：
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.github.com/packages stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23F3D4EA75716059
W: Failed to fetch https://cli.github.com/packages/dists/stable/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23F3D4EA75716059
W: Some index files failed to download. They have been ignored, or old ones used instead.
因此，根据这里的其他答案，我尝试使用以下命令更新密钥：
sudo apt-key adv --recv-key --keyserver keyserver.ubuntu.com 23F3D4EA75716059
返回的是：
Executing: /tmp/apt-key-gpghome.UZIznQa775/gpg.1.sh --recv-key --keyserver keyserver.ubuntu.com 23F3D4EA75716059
gpg: key 23F3D4EA75716059: public key "GitHub CLI <[email protected]>" imported
gpg: Total number processed: 1
gpg: imported: 1
但是当我再次运行“sudo apt-get update”时，我再次收到相同的错误（见上文）。
我几乎是个 Linux 新手。有人能看出我做错了什么吗？谢谢。
以下是 cat /etc/apt/sources.list 的输出：
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ca.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://ca.archive.ubuntu.com/ubuntu/ focal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://ca.archive.ubuntu.com/ubuntu/ focal universe
deb http://ca.archive.ubuntu.com/ubuntu/ focal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://ca.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://ca.archive.ubuntu.com/ubuntu/ focal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://ca.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu focal partner
deb-src http://archive.canonical.com/ubuntu bionic partner
deb http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://security.ubuntu.com/ubuntu focal-security universe
deb http://security.ubuntu.com/ubuntu focal-security multiverse
# deb http://archive.canonical.com/ubuntu `lsb_release -cs` partner
# deb-src http://archive.canonical.com/ubuntu `lsb_release -cs` partner