Docker packages not installing

[andybavier]

When cut-and-pasting commands from the repository's README, I hit an issue with step 1 in Get Started > Prerequisites. Running:

$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
$ echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \ $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
$ sudo apt-get update && sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin

gives the following error:

...
Get:48 http://us.archive.ubuntu.com/ubuntu focal-backports/universe i386 Packages [13.2 kB]
Get:49 http://us.archive.ubuntu.com/ubuntu focal-backports/universe amd64 Packages [23.7 kB]
Get:50 http://us.archive.ubuntu.com/ubuntu focal-backports/universe Translation-en [15.9 kB]
Get:51 http://us.archive.ubuntu.com/ubuntu focal-backports/universe amd64 c-n-f Metadata [860 B]
Reading package lists... Done
E: The repository 'https://download.docker.com/linux/ubuntu \ 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.

Looking at the docker.list file:

deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \ focal stable

I think apt is being confused by the backslash in the docker.list file. If I remove that then the install can proceed.