ubuntu - 更新 ubuntu 焦点存储库时出错

Question

我正在使用 ubuntu 20.04 并且无法更新它。通过 sudo apt update 更新时出现以下错误。所有错误都与 ubuntu 焦点有关。

sudo apt update
[sudo] password for a: 
Get:1 http://it-mirrors.evowise.com/ubuntu focal InRelease [600 kB]
Get:2 http://it-mirrors.evowise.com/ubuntu focal-updates InRelease [600 kB]
Get:3 http://it-mirrors.evowise.com/ubuntu focal-backports InRelease [600 kB]
Get:4 http://it-mirrors.evowise.com/ubuntu focal-security InRelease [600 kB]
Err:1 http://it-mirrors.evowise.com/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Err:2 http://it-mirrors.evowise.com/ubuntu focal-updates InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Err:3 http://it-mirrors.evowise.com/ubuntu focal-backports InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Err:4 http://it-mirrors.evowise.com/ubuntu focal-security InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Reading package lists... Done     
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
E: The repository 'http://it-mirrors.evowise.com/ubuntu focal InRelease' is not signed.
E: Failed to fetch http://it-mirrors.evowise.com/ubuntu/dists/focal/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
E: The repository 'http://it-mirrors.evowise.com/ubuntu focal-updates InRelease' is not signed.
E: Failed to fetch http://it-mirrors.evowise.com/ubuntu/dists/focal-updates/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://it-mirrors.evowise.com/ubuntu/dists/focal-backports/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://it-mirrors.evowise.com/ubuntu focal-backports InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://it-mirrors.evowise.com/ubuntu/dists/focal-security/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://it-mirrors.evowise.com/ubuntu focal-security InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

我的/etc/apt/sources.list.d 文件夹是空的。
然而
我的/etc/apt/sources.list 有以下几行:

# deb cdrom:[Ubuntu 20.04.2.0 LTS _Focal Fossa_ - Release amd64 (20210209.1)]/ focal main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://it-mirrors.evowise.com/ubuntu/ focal main restricted
# deb-src http://pk.archive.ubuntu.com/ubuntu/ focal main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://it-mirrors.evowise.com/ubuntu/ focal-updates main restricted
# deb-src http://pk.archive.ubuntu.com/ubuntu/ focal-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://it-mirrors.evowise.com/ubuntu/ focal universe
# deb-src http://pk.archive.ubuntu.com/ubuntu/ focal universe
deb http://it-mirrors.evowise.com/ubuntu/ focal-updates universe
# deb-src http://pk.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://it-mirrors.evowise.com/ubuntu/ focal multiverse
# deb-src http://pk.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://it-mirrors.evowise.com/ubuntu/ focal-updates multiverse
# deb-src http://pk.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://it-mirrors.evowise.com/ubuntu/ focal-backports main restricted universe multiverse
# deb-src http://pk.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 focal partner

deb http://it-mirrors.evowise.com/ubuntu/ focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://it-mirrors.evowise.com/ubuntu/ focal-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://it-mirrors.evowise.com/ubuntu/ focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse

# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.

任何解决此错误的解决方案将不胜感激。

Answer 1

我将 Ubuntu 软件“下载自”更改为“主服务器”。