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://git.osgeo.org/gitea/rttopo/librttopo/releases (?:.*?/)?(?:rel|v|librttopo)?[\-\_]?(\d\S+)\.(?:tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))