D daemon & GC?

[Dicebot via Digitalmars-d-learn]

I had similar issues. Thing is D compiler places runtime cleanup 
& initialization code into binary "constructor" sections 
(fini_array) which is needed to support shared libraries 
properly. But the same code gets triggered when you run `exit` in 
a fork resulting in attempt to terminate other process GC. There 
is an alternative "_Exit" function that should be used in forks 
instead. This is a link on topic given to me earlier by Martin 
Nowak : 
http://unix.stackexchange.com/questions/5364/why-should-a-child-of-a-vfork-or-fork-call-exit-instead-of-exit

I am not 100% this is what causes your problems but seems 
possible.