在Ubuntu下使用apt更新gitlab报错如下：
An error occurred during the signature verification.The repository is not updated and the previous index files will be used.GPG error: ...
Failed to fetch https://packages.gitlab.com/gitlab/gitlab-ee/ubuntu/dists/focal/InRelese ...
编辑如下代码并运行：
awk '/deb \[signed-by=/{
pubkey = $2;
sub(/\[signed-by=/, "", pubkey);
sub(/\]$/, "", pubkey);
print pubkey
}' /etc/apt/sources.list.d/gitlab_gitlab-?e.list | \
while read line; do
curl -s "https://packages.gitlab.com/gpg.key" | gpg --dearmor > $line
done
运行成功后，再执行apt upgrade升级gitlab，恢复正常。