[postgis-devel] Why do we still install liblwgeom includes

[Greg Troxel]

"Regina Obe" <lr at pcorp.us> writes:

>> "Regina Obe" <lr at pcorp.us> writes:
>> 
>> > I like that idea.  That include causes me nothing but grief.  I had
>> > the same issue on Debbie last week.  I had to delete liblwgeom which
>> > include got installed in the PostgreSQL folder.
>> 
>> I may be misfollowing here, but:
>> 
>> So how is this qgis processing plugin going to build?   Or are you
>> saying it's ok to break that?
> [Regina Obe] 
>
> Using liblwgeom outside of PostGIS is not supported so qgis processing
> plugin shouldn't be using it and if they are they are stuck on an old
> version.
> So any package using it is doing so at their own risk.

Which is a bit different than causing it to break, putting packagers in
a bind between
  not updating postgis
  disabling the other one
  doing something kludgy

is there a bug open in the plugins' tracket to get them to not do this?

> The issue is liblwgeom library changes with each version of PostGIS and we
> don't even guarantee it's ABI stable within a micro release, though
> generally it is.

>From a packaging point of view, the big thing is API stable, and to have
ABI breaks noted in NEWS.

> We don't want a newer PostGIS hooking to an older liblwgeom or an older
> PostGIS hooking to newer liblwgeom so we definitely don't want it installed
> in system.

This seems more about installing multiple postgis versions at once.
It's very normal to link against libraries built within the source tree
and then after installed, with -L/-R, after including headers with the
right -I flags.

Presumably then you are talking about not installing the .h and also not
installing the .so, instead somehow linking those bits into postgis.so.
Beware that libtool is fussy about mixing .a/.so, so todo this sanely is
going to need folding the lwgeom source files into the postgis library,
and essentially merging them, so that lwgeom is no longer a thing.
(That to me seems like more trouble than we have now.)

I don't think this is a big deal - just my $0.02, and if it's dropped,
anything that depends on it will almost certainly just get marked
broken.