Changes in GC and in pure space (was: [Emacs-diffs] master 5d4dd55: Fix lifetime error in previous patch)

[Eli Zaretskii]

Please be aware that these changes might potentially affect the
schedule of the Emacs 27 release.

Emacs 27 has accrued many new features and important improvements, and
has proven to be generally very stable.  My intentions were to start
its pretest in the September-October time-frame, with the goal of
releasing Emacs 27.1 a few months later.

Your changes in GC, which is a very delicate part of Emacs, might
affect its stability and force us to analyze and fix hard-to-debug
crashes, and thus postpone the beginning of the pretest and the
subsequent release.  I think we should try to avoid postponing the
27.1 release, what with the many new features it will give our users.

The same goes for removing the pure space, IMO: another core feature
whose existence and traits many parts of Emacs came to take for
granted.

I'm all for improving GC and simplifying our memory management, but
please keep the above in your minds when you play with this stuff.
Especially as, judging by the changes you are making, the details and
indeed some of the aspects of the idea of the changes, are not yet
sufficiently clear/finalized.

An alternative would be to make these changes on a branch, and merge
that branch when it is sufficiently stable and mature.  Please
consider this possibility.  After all, these two issues are not
terribly urgent to fix (unlike, say, the unexec thingy).

TIA