proj.db error on windows

[namdre]

release 1.9.0 prints

pj_obj_create: Cannot find proj.db

as error output on the console multiple times when loading a geo-referenced network with sumo or netconvert. Functionality doesn't seem to be affected

[palvarezlopez]

GDAL 6 searchs proj.db in SUMO\data\proj\proj.db, but GDAL 7 searchs proj.db in SUMO\share\proj\proj.db, and this last wasn't included in Release.

Possible solutions:

1. HotFix
2. Add extra zip file in SUMO Downloads with proj.db

Should we include proj extra files in SUMO Repository?

@behrisch What do you mean?

[behrisch]

I vote for hotfix, let's discuss it tomorrow. But I don't understand why it works nevertheless.

[palvarezlopez]

@behrisch because apparently NETCONVERT doesn't use methods implemented in proj.db

[behrisch]

But why do we ship it at all then? Just to get rid of the warning?

[palvarezlopez]

Probably there is used, (or will be used in the future), but our test cannot find a use case :-(

[namdre]

From looking into proj.db it seems to map from epsg codes to the actual geo-conversion parameters. Since we hardcode the actual conversion parameters in GeoConvHelper.cpp and our generated osm-derived .net.xml files, our tests work fine.

[namdre]

the following call only succeeds if proj.db is found:
netconvert --osm-files osm_bbox.osm.xml -o epsg.net.xml --proj "+init=epsg:4326 +to +init=epsg:25382"
(though success is relative because the resulting network still has invalid coordinates despite the code being an example for WGS84->UTM from the proj.org documentation).

I don't think this warrants a hotfix.