autorebase and user-installed dynamic objects

[Ken Brown]

On 9/20/2021 1:58 AM, ASSI wrote:
> Ken Brown via Cygwin-apps writes:
>> 1. Modify rebaseall and rebaselst to recognize 'eln' as a suffix and
>> to recognize the standard directory where emacs will install the
>> system-wide .eln files (corresponding to the preloaded libraries).
> 
> That would be which directory?

When I build emacs from the upstream repo (without setting prefix) I see

   ELN_DESTDIR='/usr/local/lib/emacs/28.0.50/

So I guess they will be in a subdirectory of /usr/lib/emacs when I build emacs 
for Cygwin.

>> 2. Create a script /usr/bin/rebaselst_usr similar to rebaselst, with a
>> few modifications:
>>
>> a) All files are in the user's home directory:
>>
>> l=${HOME}/.config/rebase
>> b=${HOME}/.cache/rebase
>> db=${l}/dynpath.d
> 
> …and there is this knotty problem.  The user has one home directory, but
> she might be using many different hosts and both Cygwin architectures.
> The rebase information is host and architecture specific.  I have no
> good solution for that yet and I don't know if XDG provides for that
> situation.  Things might have to go into /var/run/user or some similar
> location instead.  Note that the architecture dependence of eln (or
> really build dependence on a particular Emacs config if you want to be
> precise) already is a problem for Emacs in general and I haven't paid
> attention as to how they intend to solve that.

I haven't noticed any discussion of that.  I don't know about dependence on a 
particular Emacs config.  But that was never an issue for elc files, so I doubt 
if it's an issue for eln files.  There's certainly architecture dependence, but 
I don't think that will be a problem for us.  If rebase encounters a library 
intended for a different architecture, I think it will skip it, just as it skips 
in-use files, won't it?

Ken