Debugging memory leaks/stale references

[Florian Weimer]

I've decided that it's time to track down an annoying bug in Gnus (or
Emacs).  The symptom is that memory-limit keeps growing and growing,
but the data segment size (as allocated from the operating system)
remains approximately constant.  In my case, this behavior is exposed
mainly when entering large NNTP groups with Gnus.

Is it possible to dump all reachable Lisp objects to a file, in the
format that is returned by princ?  I could run diff(1) on two versions
of the file, and this might reveal which objects are leaking (or held
by stale references).  garbage-collect output alone is not very
helpful.

(I'm going to test CVS Emacs soon, just to be sure that the behavior
is still the same.  It's probably a Gnus bug, but you never know.)