Step 6/16 : RUN add-apt-repository ppa:deadsnakes/ppa -y && apt-get update && apt install python3
 ---> Running in c313222c6040
gpg: keybox '/tmp/tmpi7_iyts0/pubring.gpg' created
gpg: /tmp/tmpi7_iyts0/trustdb.gpg: trustdb created
gpg: key BA6932366A755776: public key "Launchpad PPA for deadsnakes" imported
gpg: Total number processed: 1
gpg:               imported: 1
Warning: apt-key output should not be parsed (stdout is not a terminal)
gpg: no valid OpenPGP data found.
Ign:1 http://deb.debian.org/debian stretch InRelease
Get:2 http://security.debian.org/debian-security stretch/updates InRelease [94.3 kB]
Get:3 http://deb.debian.org/debian stretch-updates InRelease [91.0 kB]
Ign:4 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal InRelease
Get:5 http://deb.debian.org/debian stretch Release [118 kB]
Get:6 https://download.docker.com/linux/ubuntu xenial InRelease [66.2 kB]
Get:7 http://deb.debian.org/debian stretch Release.gpg [2365 B]
Get:8 http://security.debian.org/debian-security stretch/updates/main amd64 Packages [500 kB]
Ign:9 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal Release
Get:10 http://deb.debian.org/debian stretch-updates/main amd64 Packages [27.9 kB]
Get:11 http://deb.debian.org/debian stretch/main amd64 Packages [7086 kB]
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Get:13 https://download.docker.com/linux/ubuntu xenial/stable amd64 Packages [11.6 kB]
Ign:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Ign:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Ign:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Ign:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Ign:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
Ign:12 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main all Packages
Err:14 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal/main amd64 Packages
  404  Not Found
Fetched 7997 kB in 2s (3681 kB/s)
Reading package lists...
W: The repository 'http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal Release' does not have a Release file.
E: Failed to fetch http://ppa.launchpad.net/deadsnakes/ppa/ubuntu/dists/focal/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
The command '/bin/sh -c add-apt-repository ppa:deadsnakes/ppa -y && apt-get update && apt install python3' returned a non-zero code: 100