I installed current TexLive afresh on a new HD under Devuan beowulf. The file I've been working on has \usepackage{siunitx) in preamble, but after with the re-installation when I run latex on it under emacs I get: Error: File `siunitx.sty' not found. I realized I had not copied the TeX packages from my old disk to the new.
So I ran $ tlmgr --gui and do "Load Default" from the ctan mirror. But get error: "Loading of remote database failed. Error message: Remote repository is newer than local (2018 < 2020)". The problem this is I'm running TeXLive 20200731. Two years ago I did run the 2018 version.
So I proceed to update my database by downloding and unzipping update-tlmgr-latest.sh. I do have /bin/sh. Here is what I get:
Verifying archive integrity... All good. Uncompressing TeX Live Manager Updater 100% ./runme.sh: Cannot find TeX Live root using kpsewhich --var-value=SELFAUTOPARENT. ./runme.sh: (no tlpkg/texlive.tlpdb and/or tlpkg/tlpobj/.) ./runme.sh: Please set your PATH as needed, otherwise it's hopeless.
I try $ tlmgr update --self (running on Debian, switching to user mode!) tlmgr: Remote repository is newer than local (2018 < 2020) Cross release updates are only supported with update-tlmgr-latest(.sh/.exe) --update Please see https://tug.org/texlive/upgrade.html for details.
The configuration:
(running on Debian, switching to user mode!) ===================== version information ======================= tlmgr revision 49885 (2019-01-31 20:27:00 +0100) tlmgr using installation: /usr/share/texlive ... PATH: /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games ... kpsewhich: /usr/bin/kpsewhich ... TEXCONFIG={{}/home/haines/.texlive2018/texmf-config,/home/haines/... ... == kpathsea variables from environment only (ok if no output here)
So it seems my TeXLive as 2018. In /home/haines there is no longer any .texlfive directory. In ~/.profile there is:
PATH=/usr/local/texlive/2020/bin/x86_64-linux:$PATH; export PATH
PATH=/usr/local/texlive/2020/bin/x86_64-linux:$PATH
would be the default location for a vanilla texlive installed from TUG,running on Debian, switching to user mode
implies that you are using a debian packaged texlive (which should be updated with apt packages not tlmgr. Do you have two conflicting installations?