[Qgis-developer] Why does python-qgis depend on liblwgeom?

[Sebastiaan Couwenberg]

The python-qgis package now includes a dependency on liblwgeom for the
Debian distributions, but not Ubuntu. A build dependency on
liblwgeom-dev was not added along with the dependency in the commit. [0]

Why does python-qgis depend on the liblwgeom library package?

liblwgeom is not used in the build process, so ${shlibs:Depends} doesn't
include the dependency automatically.

I suspect the dependency was added to have the liblwgeom package
installed already when users choose to install the Processing LWGEOM
Provider plugin.

The plugin source show that it searches for liblwgeom.so which is
provided by the liblwgeom-dev package. Because the plugin doesn't try
the Multi-Arch paths, so when the postgis package changes to Multi-Arch
paths the plugin will stop working.

Because the python-qgis package doesn't seem to require liblwgeom
itself, including it in its Depends is not appropriate, Recommends
should be used instead.

It's also better to not depend on the library package directly, and
instead depend on liblwgeom-dev which will pull in the appropriate
library package removing the need to change the dependency every time
the liblwgeom SONAME changes.

[0]
https://github.com/qgis/QGIS/commit/f2d4d3083b765029e981b4638bc80bf828ece6a7

Kind Regards,

Bas

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