Tile data is generated with missing shapes

[Gaibhne]

The project.mml file is referring to missing data sources data/river-polygons-reduced and data/ocean-polygons-reduced. Generating the Mapnik XML from this mml leads to errors about non-existant shapes (as these sources are rightfully commented out in the shape downloader). Simply deleting these sources in the project.mml file leads to missing features in the resulting map.

What can be done about it ?

[giggls]

They used to be downloadable from http://openstreetmapdata.com
Unfortunately, as this service has been discontinued, there is no download alternate yet.
The ones I currently use are available from https://tile.openstreetmap.de/shapefiles/ for now,
but they are currently not updated.

[Gaibhne]

Does that mean that this project is currently unusable with its existing scripts, unless I happen to have downloaded older versions in the past or manually download these outdated versions ? Can not whatever versions the upstream project uses be used ?

[giggls]

OK, a bit of explanation. I am quite shure that you would not have noticed that these files are "outdated" if I would have hidden the fact. We are talking lowzoom (0-6) here after all.

I am using get-shapefiles.py in a cronjob, thats why the download is disabled there. Using the ones I provided for you is fine IMO.

It does not happen that often after all, that objects of the size visible in those zoomlevels will change its shape in a noticeable way.

I did not yet recover the more ugly rendering from upstream because I still hope that we can recover the build-process of the reduced shape files. I already contacted @imagico about this.

[Gaibhne]

Thank you for the explanation. I was not aware what exactly the shapefiles are for, since I have yet to get this fork working; the differences to the upstream are so numerous that I have yet to work through everything needed to actually get anything to render. I wasn't aware that the upstream versions are uglier, nor that the files are something that is rarely changed. Thank you for clearing that up, it seems like it will be perfectly fine for us to use the 'outdated' ones then - I'm not even sure we allow zoom levels that crude on our platform.

I would still argue that this repo should be changed, whether through using the upstream ones, the outdated ones, the outdated ones as a fallback or through at least a notice of some sort. I found myself simply cloning the repo, following all the installation steps, and ending up with a nonfunctional carto installation would would crash the renderd threads, unable to, as far as I can tell, render anything at any zoom levels. Even if I personally got your help, the next person might not find this issue and your answer.

[giggls]

In contrast to upstream I provide a makefile which will render one tile per zoom level and features different from upstream. I did not consider this difficult up till now.
Just to make shure. You did read INSTALL-de.md?

[Gaibhne]

I did, and my problems in no way stem from the project being unworkable in its own (other than the issue with the missing shapes), but from integrating it in another project, that expects many things to be the same that aren't. But that is absolutely not your fault or in fact a problem with this fork at all, merely the explanation why I personally have not yet got it working in the way I'm trying to. I did of course read the German-specific INSTALL file.