The backstory: To bypass internet censorship and deep packet inspection, I had written a proxy chain solution masquerading itself as plain html traffic. I needed it constantly running everywhere I went, but I didn't want to port it to a native android app. I wanted to run it through termux and at the time termux had no jdk/jre. Proot could spawn a archlinux env and there indeed was a jdk available.
The arch env within termux turned out to be generally more suitable for all tasks. Creating and destroying ephemeral envs with different setups and prooting into them to just run a single command is easily automated with a script; I named it bag.sh, a drastically smaller form of a shipping container.
Funny bag.sh also has a roadmap/todo in there untouched for 5 years! It's written on mobile screen hence mostly formatted to 40 columns lines to fit on the display without scrolling.