bug#29220: 26.0.90; eieio-persistent-read fail to restore saved object.

[Eric Abrahamsen]

On 05/27/19 19:36 PM, Noam Postavsky wrote:
> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>>>> Bah, this is annoyingly difficult -- thank you for trying it out. I
>>>> suppose one terrible heuristic would be if the errors were different
>>>> between emacs-25, emacs-26, and fix/eieio-persistent. Would you mind
>>>> sending me the error output, in case anything jumps out at me?
>>>>
>>> Hope this could help you.
>>
>> Thanks. They all end in "Corrupt object on disk", which is an
>> eieio-persist problem. I'll keep working on this.
>
> So, I think it would be nice to have this fixed for 26.3.  It sounds
> like the fix you're working on is too risky to have on a release branch
> regardless of its current status, so here's a patch which makes eieio
> objects use symbols as type tags, when eieio-backward-compatibility is
> non-nil.  Folks who want the record-with-circular-references as type
> tags can still get that by setting eieio-backward-compatibility to nil.

I agree that everything I came up with is too shaky for a release
branch. I haven't tried your solution, but it looks simple enough.

Despite much help from many people, this problem ultimately defeated me.
I was trying to come up with a universal solution that would work for
any object, and after a couple of months had something that worked for
restoring objects, but then realized that it wouldn't work for saving
them. Whereupon I deflated like a cheap balloon. This is just beyond my
skills right now.

Eric