Gregory's Server
...and all the usage instructions just as prominently recommend using a pre-built Docker image provided by them.
Should you file a bug report, where all signs point to a rather obvious issue in their code, and happen to mention that you weren't in fact using Docker, but just built the software in the natural & straightforward way, the maintainers close the report, saying that non-Docker builds are unsupported, ...
2/3
since they don't have the capacity nor the desire to support the multitude of differing environments & distros.
Finally, upon startup, the software checks to see if it's running inside Docker, and prints a loud & annoying warning about an unsupported configuration otherwise.
3/3