Thank you for an answer. That's what I was suspecting. It would be nice it if it would be mentioned somewhere in the documentation (maybe it is, I was unable to find it). I am trying to load libhostfxr.dylib, which is shipped with .NET installation on the system and would allow me to host .NET runtime in my process.

I do not. It is an LaunchDaemon bundled as an app bundle. I am not even sure if it is GateKeeper that kills it, all I was able to find was crash report with code signing specified as an reason of the crash.