[gdal-dev] spatialite on Debian: neither lwgeom nor rttopo

[Bas Couwenberg]

On 2018-02-19 15:40, Tobias Wendorff wrote:
> Am Mo, 19.02.2018, 07:40 schrieb Sebastiaan Couwenberg:
>> lwgeom support was disabled to untangle the circular dependency as
>> documented in the spatialite changelog:
>> 
>>  - Drop build dependency on liblwgeom-dev to untangle
>>    spatialite->postgis->gdal->spatialite circular dependency.
> 
> Please excuse my amateurism, but could you explain this in more detail?
> I do have a certain understanding of the matter, but I've never had
> anything to do with such circular dependencies.

Packages involved in the circular dependency cannot be updated because 
the old versions are kept around.

See:

  https://lists.debian.org/debian-gis/2016/02/msg00017.html
  https://lists.debian.org/debian-gis/2015/08/msg00061.html

When performing a distribution upgrade apt will need to update 
libspatialite, which involves removing the old version and installing 
the new.

This will not be possible because gdal requires libspatialite to be 
installed.

Removing gdal before upgrading libspatialite is not possible because 
postgis requires gdal to be installed.

Removing postgis before upgrading libspatialite and gdal is not possible 
because libspatialite requires (liblwgeom from) postgis to be installed.

Kind Regards,

Bas