apt-get update извлекает зависимости пакета, которые не определены в sources.list

Когда я вызываю sudo apt-get update , я получаю сообщение об ошибке при резервном копировании моего доступного скрипта.

$ sudo apt-get update
Ign:2 http://mirror.local.url.uk/debian stretch InRelease
Hit:3 http://mirror.local.url.uk/debian stretch Release
Hit:4 http://security.debian.org/debian-security stretch/updates InRelease
Ign:1 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch InRelease
Ign:6 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch Release
Ign:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:11 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:11 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:12 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:12 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:13 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:13 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:11 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:11 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:12 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:12 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:13 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:13 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:11 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:11 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:12 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:12 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:13 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:13 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:11 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:11 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:12 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:12 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:13 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:13 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Ign:11 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:11 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main i386 Packages
Ign:12 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:12 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en_GB
Ign:13 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Ign:13 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Translation-en
Err:7 http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
  404  Not Found
Ign:7 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main Sources
Ign:8 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main amd64 Packages
Ign:9 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main ppc64el Packages
Ign:10 https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch/main all Packages
Reading package lists... Done
W: The repository 'http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian stretch Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian/dists/stretch/main/source/Sources  404  Not Found
E: Failed to fetch https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian/dists/stretch/main/binary-i386/Packages  404  Not Found
E: Failed to fetch https://mirror.sax.uk.as61049.net/mirror/mariadb.org/repo/10.3/debian/dists/stretch/main/i18n/Translation-en_GB  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

И все же мой файл sources.list выглядит так:

# deb http://mirror.local.url.uk/debian stretch main

deb http://mirror.local.url.uk/debian stretch main non-free contrib
deb-src http://mirror.local.url.uk/debian stretch main non-free contrib

deb http://security.debian.org/debian-security stretch/updates main contrib non-free
deb-src http://security.debian.org/debian-security stretch/updates main contrib non-free

# stretch-updates, previously known as 'volatile'
# deb http://mirror.local.url.uk/debian stretch-updates main contrib non-free
# deb-src http://mirror.local.url.uk/debian stretch-updates main contrib non-free

Как удалить проблемный http://mirror.sax.uk.as61049.net/mirror/mariadb.org запись из процесса обновления apt-get?