Request #68271 has been Rejected by MarsSeed [1]: Former maintainer Maxime Arthaud / @arthaud has disowned the package.
Thank you, Maxime, for your email response. Apparently upstream has neglected to update their old website for many many years (now offline as well), which in turn has failed to reflect the fact that their GitHub repository had newer releases since 2019. [1] https://aur.archlinux.org/account/MarsSeed/
