Re: Obtaining a database of new functionality per Emacs version

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 10 Dec 2020 10:31:18 +0300
> From: Jean Louis <bugs@gnu.support>
> 
> * Vasilij Schneidermann <mail@vasilij.de> [2020-12-07 16:30]:
> > Hello everyone,
> > 
> > I'm looking into creating a tool helping me with ensuring that my
> > packages actually support the Emacs versions they claim to by
> > highlighting uses of unsupported functions/variables [1]. 
> 
> If one could launch automatically various Emacs versions and obtain a
> list of all functions and all variables, by also keeping those flags
> if variable is obsolete or not, or function is obsolete or not, then
> such lists could be exported for each Emacs version and their
> differences easily found.

You do realize that Vasilij wanted to know ab out _all_ the functions,
not just those present in "emacs -Q"?  To do what he wanted, you'd
need to load all of the Emacs packages as well, one by one, taking
care to unload them or restart the session, to account for basic
incompatibilities between some of them.  I don't think this is a
practical solution.