Linux Deploy is a pretty nice app on Android.
I finished porting this site to Frog a few days ago. There isn't a package for Racket in Termux — Termux provides packages for Jekyll and Hugo, but I still don't really understand them, and I'm using Frog right now — but with Linux Deploy, I could create an environment (sort of like a container?) and install Debian Sid into it, enable SSH, bind
/sdcard into it, install Racket and Frog inside, and now I can build this site on my phone.
It'd be better if Termux itself provides packages for Racket though. My battery drains really fast when this container(?) is started.