本地安装Ubuntu 22.04.1 LTS 后报 Clearsigned file isn't valid 相关错误。
root@ubuntu:/etc/apt# cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.1 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
root@ubuntu:/etc/apt#
报错信息：
root@ubuntu:/etc/apt# sudo apt-get update Clearsigned file isn't valid
Get:1 http://archive.ubuntu.com/ubuntu jammy InRelease [2,664 B]
Err:1 http://archive.ubuntu.com/ubuntu jammy InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:2 http://security.ubuntu.com/ubuntu jammy-security InRelease [2,664 B]
Err:2 http://security.ubuntu.com/ubuntu jammy-security InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:3 http://archive.ubuntu.com/ubuntu jammy-updates InRelease [2,664 B]
Err:3 http://archive.ubuntu.com/ubuntu jammy-updates InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:4 http://archive.ubuntu.com/ubuntu jammy-backports InRelease [2,664 B]
Err:4 http://archive.ubuntu.com/ubuntu jammy-backports 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://archive.ubuntu.com/ubuntu jammy InRelease' is not signed.
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy/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://security.ubuntu.com/ubuntu jammy-security InRelease' is not signed.
E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/jammy-security/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://archive.ubuntu.com/ubuntu jammy-updates 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://archive.ubuntu.com/ubuntu/dists/jammy-backports/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://archive.ubuntu.com/ubuntu jammy-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.
root@ubuntu:/etc/apt#
初步可以认定为网络问题。因此解决方式，可通过调整网络或切换国内源解决。
1、切换网络，使用代理软件即可。亲测可行。
2、更换apt源。以下采用此方法解决。
初始安装，可以查看默认配置为：
root@ubuntu:/etc/apt# cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.1 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
root@ubuntu:/etc/apt# clear
root@ubuntu:/etc/apt# pwd
/etc/apt
root@ubuntu:/etc/apt# cat /etc/apt/sources.list
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu/ jammy main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ jammy main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ jammy-updates main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ jammy-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://archive.ubuntu.com/ubuntu/ jammy universe
# deb-src http://archive.ubuntu.com/ubuntu/ jammy universe
deb http://archive.ubuntu.com/ubuntu/ jammy-updates universe
# deb-src http://archive.ubuntu.com/ubuntu/ jammy-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://archive.ubuntu.com/ubuntu/ jammy multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ jammy multiverse
deb http://archive.ubuntu.com/ubuntu/ jammy-updates multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ jammy-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://archive.ubuntu.com/ubuntu/ jammy-backports main restricted universe multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ jammy-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted
# deb-src http://security.ubuntu.com/ubuntu/ jammy-security main restricted
deb http://security.ubuntu.com/ubuntu/ jammy-security universe
# deb-src http://security.ubuntu.com/ubuntu/ jammy-security universe
deb http://security.ubuntu.com/ubuntu/ jammy-security multiverse
# deb-src http://security.ubuntu.com/ubuntu/ jammy-security multiverse
root@ubuntu:/etc/apt#
因此将以上*ubuntu.com替换成国内源地址即可，
如华为源：http://repo.huaweicloud.com/ubuntu/,其他源参考替换即可
sudo sed -i "s@http://.*archive.ubuntu.com@http://repo.huaweicloud.com@g" /etc/apt/sources.list
sudo sed -i "s@http://.*security.ubuntu.com@http://repo.huaweicloud.com@g" /etc/apt/sources.list
执行命令
sudo apt-get update
root@ubuntu:/etc/apt# sudo apt-get update
Hit:1 http://repo.huaweicloud.com/ubuntu jammy InRelease
Hit:2 http://repo.huaweicloud.com/ubuntu jammy-updates InRelease
Hit:3 http://repo.huaweicloud.com/ubuntu jammy-backports InRelease
Hit:4 http://repo.huaweicloud.com/ubuntu jammy-security InRelease
Reading package lists... Done
root@ubuntu:/etc/apt#
至此，问题已经得到解决。
附录：
部分虚拟机安装不上ubuntu，很可能是hyper-v冲突。
因此将hyper-v从电脑中卸除。可以开始安装vmware虚拟机软件或者其他第三方虚拟机软件。管理权限打开powsershell执行命令，重启系统即可。
bcdedit /set hypervisorlaunchtype off