Program crash: GC destroys an object unexpectedly

[eugene]

On Monday, 13 September 2021 at 17:40:41 UTC, user1234 wrote:
> The problems seems to lies in `newSignal()` which "would" not 
> allocate using the GC.

     final Signal newSignal(int signum) {
         Signal sg = new Signal(signum);
         sg.owner = this;
         sg.number = sg_number++;
         sg.register();
         return sg;
     }

full src is here
http://zed.karelia.ru/0/e/edsm-in-d-2021-09-10.tar.gz