Trying to follow the instructions at https://github.com/roundup-tracker/roundup/blob/26224d88324b9bb9e394e7c3f2cb66e5dd03213d/doc/developers.txt#L117, I `hg clone`'d the repository and executed
ross@barley:/usr/local/src/roundup$ date; python3 ./demo -b sqlite
Sun 17 May 2026 11:13:48 PM PDT
python3: can't open file '/usr/local/src/roundup/./demo': [Errno 2] No such file or directory

I changed that to `./demo.py` and was able to start the program.

I think 2 things are missing from the instructions:

  1. Instructions to change to the project root directory.
  2. `.py` at the end of `./demo`.

Running Python 3.9 in a bash shell on Debian GNU/Linux 11 (old).