Incremental TeX-Live ?

[Andreas Scherer]

 > it seems to me that considerable time could be saved when performing
 > a full install if the previous year's files could be used
Although my .bashrc on Linux has this nice loop

# set PATH so it includes TeXLive's bin, if it exists
for y in {2015..2020}
do
     if [ -d /opt/texlive/$y/bin/x86_64-linux ]; then
         PATH="${PATH}":/opt/texlive/$y/bin/x86_64-linux
     fi
done

for nostalgic reasons, the installation path /opt/texlive only holds 
"2020" ATTOW (and a soft link 'current->2020').  My backup media only 
hold copies of the past two or three years.  I think that since 2016 I 
never did a "full installation", but upgraded the "infrastructure" and 
pulled the updated packages with "tlmgr update --all".  This, in fact, 
saved a lot of time and bandwidth. :o)

Last year, I even succeeded to upgrade a "BasicTeX" installation on 
MacOS "High Sierra" manually.  This process was far less pleasant, but 
quite insightful.  Luckily, my private Mac Mini runs "Catalina", so I 
guess it will be simple to install the next "BasicTeX 2021" package.

(Un)fortunately, I have no experience with TeX Live on MS Windows.

On a different note, I'd find it quite interesting to put consecutive 
vintages of the TeX Live installation under "version control".  This 
should eliminate unchanged duplicates and permit to invoke "TeX and 
friends" from cleanly separated timestamps.  I did something like this 
for CWEB: https://github.com/ascherer/cweb/releases and find it quite 
instructive to scroll through the years of CWEB's developments.

Cheers, Andreas