The package has a debian/watch file, but the last attempt
to use it for checking for newer upstream versions failed with
an error:
In debian/watch no matching files for watch line https://github.com/ashinn/chibi-scheme/releases .*/v?(?:[-_]?[Vv]?(\d[\-+\.:\~\da-zA-Z]*))(?i)(?:\.(?:tar\.xz|tar\.bz2|tar\.gz|tar\.zstd?|zip|tgz|tbz|txz))