W: Failed to fetch http://mariadb.mirror.nucleus.be//repo/10.1/debian/dists/sid/main/source/Sources  404  Not Found [IP: 2a03:a800:2:1::5 80]

W: Failed to fetch http://mariadb.mirror.nucleus.be//repo/10.1/debian/dists/sid/main/binary-amd64/Packages  404  Not Found [IP: 2a03:a800:2:1::5 80]

W: Failed to fetch http://mariadb.mirror.nucleus.be//repo/10.1/debian/dists/sid/main/binary-i386/Packages  404  Not Found [IP: 2a03:a800:2:1::5 80]

W: Failed to fetch http://mariadb.cu.be//repo/10.1/debian/dists/sid/main/source/Sources  404  Not Found [IP: 2001:67c:314::feed:feef 80]

W: Failed to fetch http://mariadb.cu.be//repo/10.1/debian/dists/sid/main/binary-amd64/Packages  404  Not Found [IP: 2001:67c:314::feed:feef 80]

W: Failed to fetch http://mariadb.cu.be//repo/10.1/debian/dists/sid/main/binary-i386/Packages  404  Not Found [IP: 2001:67c:314::feed:feef 80]

W: Failed to fetch http://mirror.klaus-uwe.me/mariadb/repo/10.1/debian/dists/sid/main/source/Sources  404  Not Found [IP: 2001:15c0:65ff:7b4::2 80]

W: Failed to fetch http://mirror.klaus-uwe.me/mariadb/repo/10.1/debian/dists/sid/main/binary-amd64/Packages  404  Not Found [IP: 2001:15c0:65ff:7b4::2 80]

W: Failed to fetch http://mirror.klaus-uwe.me/mariadb/repo/10.1/debian/dists/sid/main/binary-i386/Packages  404  Not Found [IP: 2001:15c0:65ff:7b4::2 80]

E: Some index files failed to download. They have been ignored, or old ones used instead.