Thanks. That's a great resource. At this stage I am trying to update R. I suppose the next stage will be to update packages. When I follow the instructions, I update the/etc/apt/sources.list file to include the last line shown below (letting you see entire file)
deb https://deb.debian.org/debian buster main
deb https://security.debian.org/debian-security buster/updates main
deb https://cloud.r-project.org/bin/linux/debian buster-cran40/
Then I apply the command line
sudo apt-get update
apt-get install r-base r-base-dev
The first line produces:
xer0925@penguin:~$ sudo apt-get update
Hit:1 https://deb.debian.org/debian buster InRelease
Ign:2 https://storage.googleapis.com/cros-packages/96 buster InRelease
Get:3 https://cloud.r-project.org/bin/linux/debian buster-cran40/ InRelease [4,363 B]
Ign:4 http://ppa.launchpad.net/c2d4u.team/c2d4u4.0+/ubuntu jammy InRelease
Hit:5 https://storage.googleapis.com/cros-packages/96 buster Release
Hit:6 https://security.debian.org/debian-security buster/updates InRelease
Err:7 http://ppa.launchpad.net/c2d4u.team/c2d4u4.0+/ubuntu jammy Release
404 Not Found [IP: 91.189.95.85 80]
Err:3 https://cloud.r-project.org/bin/linux/debian buster-cran40/ InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B8F25A8A73EACF41
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/c2d4u.team/c2d4u4.0+/ubuntu jammy 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.
W: GPG error: https://cloud.r-project.org/bin/linux/debian buster-cran40/ InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B8F25A8A73EACF41
E: The repository 'https://cloud.r-project.org/bin/linux/debian buster-cran40/ 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.
W: Target Packages (Packages) is configured multiple times in /etc/apt/sources.list:4 and /etc/apt/sources.list.d/r.list:1
W: Target Translations (en_US) is configured multiple times in /etc/apt/sources.list:4 and /etc/apt/sources.list.d/r.list:1
W: Target Translations (en) is configured multiple times in /etc/apt/sources.list:4 and /etc/apt/sources.list.d/r.list:1
Still I try the second command and get:
xer0925@penguin:~$ sudo apt-get install r-base r-base-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
r-base is already the newest version (3.5.2-1).
r-base-dev is already the newest version (3.5.2-1).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
And to make sure it didn't update:
xer0925@penguin:~$ R --version
R version 3.5.2 (2018-12-20) -- "Eggshell Igloo"
Copyright (C) 2018 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
http://www.gnu.org/licenses/.
Any suggestions as to what I should try next? Thanks.