$ sudo apt update
[sudo] password for mostafa:
Hit:1 http://ir.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://ir.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:3 http://ir.archive.ubuntu.com/ubuntu focal-backports InRelease
Get:4 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Hit:5 http://packages.microsoft.com/repos/code stable InRelease
Hit:6 http://archive.canonical.com focal InRelease
Hit:7 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:8 http://cz.archive.ubuntu.com/ubuntu focal InRelease
Hit:9 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:10 http://ppa.launchpad.net/apandada1/brightness-controller/ubuntu focal InRelease
Get:11 https://dl.winehq.org/wine-builds/ubuntu focal InRelease [8,041 B]
Hit:12 https://download.docker.com/linux/ubuntu focal InRelease
Hit:13 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal InRelease
Hit:14 http://ppa.launchpad.net/deluge-team/stable/ubuntu focal InRelease
Hit:15 http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu focal InRelease
Get:16 https://dl.winehq.org/wine-builds/ubuntu focal/main i386 Packages [372 kB]
Hit:17 http://ppa.launchpad.net/micahflee/ppa/ubuntu focal InRelease
Get:18 https://dl.winehq.org/wine-builds/ubuntu focal/main amd64 Packages [370 kB]
Get:19 http://security.ubuntu.com/ubuntu focal-security/main amd64 DEP-11 Metadata [40.7 kB]
Ign:20 http://ppa.launchpad.net/nathan-renniewaldock/flux/ubuntu focal InRelease
Get:21 http://security.ubuntu.com/ubuntu focal-security/universe amd64 DEP-11 Metadata [94.2 kB]
Hit:22 http://ppa.launchpad.net/savoury1/digikam/ubuntu focal InRelease
Get:23 http://security.ubuntu.com/ubuntu focal-security/multiverse amd64 DEP-11 Metadata [940 B]
Err:24 http://ppa.launchpad.net/nathan-renniewaldock/flux/ubuntu focal Release
404 Not Found [IP: 204.12.224.146 80]
Ign:25 https://repo.skype.com/deb stable InRelease
Err:26 https://repo.skype.com/deb stable Release
Could not wait for server fd - select (11: Resource temporarily unavailable) [IP: 148.251.160.243 443]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/nathan-renniewaldock/flux/ubuntu focal Release' does not have a Release file.
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: The repository 'https://repo.skype.com/deb stable Release' does not have a Release file.
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.
sudo apt install ppa-purge
sudo ppa-purge ppa:nathan-renniewaldock/flux
دروددلیل اینکه اونها رو ایمن تشخیص نداده این هست که اون مخزن Release file نداره، دلیل اینکه Release file نداره این هست که اون مخزن چیزی برای اوبونتو ۲۰.۰۴ نداره.
یسری مخازن رو ایمن تشخیص نداده و بصورت پیشفرض اونارو غیر فعال کرده و ازشون لیست رو اپدیت نمیکنه