About a year ago I filed a bug [1] asking for a maintainer for geiser. Unfortunately no-one showed interest in doing that. I was just trying to understand someones comment on IRC and ran the debian version of geiser. As far as I can tell it seems incompatible with emacs 26, and should probably be removed from buster. I tried 0.10 from melpa stable, and it seems better, although there is still some issue related to requiring ilisp (I didn't track down what was requiring ilisp).
My current plan is to file an RC bug on elpa-geiser to keep it out of buster, and perhaps do an upload of 0.10 to experimental. The diff from 0.8.1 to 0.10 is too large for a freeze exception IMHO. I'm currently not sure if the changes for emacs 26 compatibility are backportable. If someone else cares about geiser, now would be a good time to contribute. [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=897140
