Texlive 2021: tlmgr

I have installed Texlive 2021 on Ubuntu 21.04 on a new laptop. There aren't previous version of Texlive in the system. I have had to install it as root user since, while trying to install it as simple user he didn't let the installer write in some directories.

Following, the guide I have updated the paths in the $HOME/.profile file adding the following expressions:

if [ -d "/usr/local/texlive/2021/bin/x86_64-linux" ] ; then
    PATH="$HOME/usr/local/texlive/2021/bin/x86_64-linux:$PATH"
    fi
if [ -d "/usr/local/texlive/2021/texmf-dist/doc/man" ] ; then
    MANPATH="/usr/local/texlive/2021/texmf-dist/doc/man:$MANPATH"
    fi
 if [ -d "/usr/local/texlive/2021/texmf-dist/doc/info" ] ; then
    INFOPATH="/usr/local/texlive/2021/texmf-dist/doc/info:$INFOPATH"
    fi

This way Latex works fine. As for tlmgr, in root mode, I can open and operate the GUI.
I tried, still in root mode (in user mode ir says I have to run it in root mode)

tlmgr update --self (and > tlmgr update --self)

It gave me the following message:

(running on Debian, switching to user mode!)
(see /usr/share/doc/texlive-base/README.tlmgr-on-Debian.md)
TLPDB: not a directory, not loading: /root/texmf
tlmgr: user mode not initialized, please read the documentation!

I tried to employ --usermode and --usertree with no success. Finally I wrote

PATH=/usr/local/texlive/2021/bin/x86_64-linux:$PATH; export PATH MANPATH=/usr/local/texlive/2021/texmf-dist/doc/man:$MANPATH; export MANPATH
INFOPATH=/usr/local/texlive/2021/texmf-dist/doc/info:$INFOPATH; > export INFOPATH

This way it works. Any alternative, that saves me copying and pasting those instruction? When writing

echo $PATH
echo $MANPATH
echo $INFOPATH

the terminal lists the corrects directories. What's missing? I think I should set a PATH, but where?

UPDATE! (partially solved but not quite)

I copied the $PATH, $MANPATH, $INFOPATH on the .basch file. Now

tlmgr update -all

works fine Unfortunately

tlmgr update --self

responds this way.

tlmgr: Local TeX Live (2020) is older than remote repository (2021). Cross release updates are only supported with update-tlmgr-latest(.sh/.exe) --update See https://tug.org/texlive/upgrade.html for details.

I have tried to follow the suggestions on the upgrade page of tug.org/texlive without success.

Any idea?

TexLive ecosystem is very mature, so having latest 2021 version is not really needed on real life situations. Personally I find the usage of binary TeXLive distribution from tug.org/texlive non-reproducible and too windows-way. I would recommend to remove it.

Reallly I would recommend two things to do on fresh laptop:

1. Run a fresh install of Ubuntu 20.04 LTS to have bright future for next 4 years. This version is LTS - long-term support (5 years of support starting from 2020 April), so you should not run unnecessary distribution upgrades in each 9-months frames as it will with 21.04.

2. Install TeXLive 2019 from official Ubuntu repositories as simple as

   sudo add-apt-repository universe
   sudo apt-get install texlive-full
   

   You should imagine the situation when your other systems exist. For example - home laptop and workstation at work. Installation of deb-packages is always reproducible and straight-forward procedure with 100% success.