How to debug long-lived D program memory usage?

[Adam D. Ruppe]

On Wednesday, 17 April 2019 at 23:57:41 UTC, Meta wrote:
> Not at all what you want, but it may be useful for figuring out 
> where the leaks are. Have you tried compiling with -vgc?

That wouldn't help me much here because I know parts are GC 
allocating, and I'm ok with that. What I want to know are the 
parts the GC is not collecting for whatever reason. These parts 
may be malloc'd too; it isn't necessary the GC's fault.