multiverse repository update warning message

Question

for installing MS-core-fonts i just added following repository to ubuntu 21.04:

sudo add-apt-repository multiverse

now, everytime i run apt update command i get following warning message several times:

$ sudo apt update
Hit:1 http://archive.ubuntu.com/ubuntu hirsute InRelease
Hit:2 http://archive.ubuntu.com/ubuntu hirsute-updates InRelease
Hit:3 http://archive.canonical.com/ubuntu hirsute InRelease
Hit:4 http://archive.ubuntu.com/ubuntu hirsute-backports InRelease
Get:5 http://archive.ubuntu.com/ubuntu hirsute-security InRelease [101 kB]
Fetched 101 kB in 2s (65.3 kB/s)   
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.
W: Skipping acquire of configured file 'multiverse/binary-i386/Packages' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/binary-amd64/Packages' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-fa_IR' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-fa' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-en' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/Components-amd64.yml' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/icons-48x48.tar' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/icons-64x64.tar' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/icons-64x64@2.tar' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/cnf/Commands-amd64' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)

i noticed multiverse repository was active in ubuntu software even before adding that repository but there was not such an error before.

the resault /etc/apt/sources.list is as follows:

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu hirsute restricted main multiverse
Major bug fix updates produced after the final release of the
distribution.
deb http://archive.ubuntu.com/ubuntu hirsute-updates restricted main multiverse
N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
team. Also, please note that software in universe WILL NOT receive any
review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu hirsute universe
deb http://archive.ubuntu.com/ubuntu hirsute-updates universe
N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
team, and may not be under a free licence. Please satisfy yourself as to
your rights to use the software. Also, please note that software in
multiverse WILL NOT receive any review or updates from the Ubuntu
security team.
N.B. software from this repository may not have been tested as
extensively as that contained in the main release, although it includes
newer versions of some applications which may provide useful features.
Also, please note that software in backports WILL NOT receive any review
or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu hirsute-backports universe restricted main multiverse
Uncomment the following two lines to add software from Canonical's
'partner' repository.
This software is not part of Ubuntu, but is offered by Canonical and the
respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu hirsute multiverse partner
deb http://archive.ubuntu.com/ubuntu hirsute-security restricted main multiverse
deb http://archive.ubuntu.com/ubuntu hirsute-security universe

So, what is the problem now with multiverse repository?

Answer 1

@RayWoodcock explained it very well:

[T]he basic idea is that your sources.list was trying to get multiverse content from a repository that doesn't have multiverse content. The word "multiverse" was added automatically to some repositories in sources.list, and had to be removed manually from the one(s) with no multiverse material.

http://archive.canonical.com/ubuntu is not a general purpose repository. You are getting those warnings because you are erroneously trying to treat that source as general-purpose.

Here, let's take a look:

W: Skipping acquire of configured file 'multiverse/binary-i386/Packages'
 as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' 
 doesn't have the component 'multiverse' (component misspelt in sources.list?)

See? "Source X doesn't have 'multiverse'". And X is http://archive.canonical.com/ubuntu

That source should ONLY be used for the partner repo. Delete it's use for everything else.

Line 31 of your file currently reads:

deb http://archive.canonical.com/ubuntu hirsute multiverse partner

Edit the file so that line instead reads:

deb http://archive.canonical.com/ubuntu hirsute partner

See how multiverse has been removed from the line?

Finally, since you have changed your sources,

sudo apt update