Note that I have only tested building Csup on Ubuntu 22.04 and Linux Mint 21. It may work on other distros, but I have not tried them.

Install the Crystal language according to these instructions.

Make sure you have the ncursesw packages installed. On Debian/Ubuntu do this:

sudo apt install libncursesw5 libncursesw5-dev

Fetch the source code repository and check it out in one step using:

fossil clone https://www.bloovis.com/fossil/home/marka/fossils/csup

Change to the csup directory and build it:

cd csup
shards install
make

Copy the binary (csup) to some place in your PATH.