autorebase and user-installed dynamic objects

[Ken Brown]

On 9/19/2021 12:39 PM, Achim Gratz wrote:
> Ken Brown via Cygwin-apps writes:
>> A per-user database sounds like a good idea.
> 
> Well, the problem is how to maintain it.  So let's for the moment skip
> that part and see if it would work when we pretend we'd already solved
> that problem.  An ephemeral rebase is essentially a user-defined
> database that gets thrown away immediately, so you can not re-use its
> information.  We would need to replace emacs with a wrapper script that
> checks a cookie file against the system wide rebase database and if the
> latter is newer, trigger an ephemeral rebase of the emacs user
> directory.  The same should be done for each compilation.  If that
> works, then we can try to figure out how to not constantly rebase stuff
> that doesn't need to get rebased again via some sort of user rebase
> database.

I'm not sure the rebase of the emacs user directory has to be ephemeral.  First 
of all, I think we should make /var/lib/rebase/user.d/<username> work as 
documented.  Users could list their emacs user directory there, and people who 
build emacs themselves could also list their emacs build directory.  That way 
things could be kept reasonably stable in the long run via the autorebase 
postinstall script.  Implicit in this is that the results of all these rebases 
would be stored in the user's rebase database.

After each compilation, but before the new .eln file is loaded, emacs could call 
rebaselst with suitable arguments to rebase that new file (and add it to the 
user database).

Ken