Mapnik produces water-filled tiles at zoom=18 for big area in Siberia

[openstreetmap-trac]

Reporter: pvm96[at]yandex.ru
[Submitted to the original trac issue database at 9.34am, Monday, 11th March 2013]

If you look at any place inside this area zoomed at level 18, you'll see that the whole area is filled with water, even where there is ground:
http://www.openstreetmap.org/?box=yes&bbox=81.23549%2C54.060041%2C85.627667%2C68.841992

Some pictures of the edges of this effect are:
East
http://www.openstreetmap.org/?lat=55.27545&lon=85.627667&zoom=18&layers=M
South
http://www.openstreetmap.org/?lat=54.08514&lon=83.40566&zoom=18&layers=M
West
http://www.openstreetmap.org/?lat=58.858448&lon=81.23549&zoom=18&layers=M
North
http://www.openstreetmap.org/?lat=68.841992&lon=82.550755&zoom=18&layers=M

I've found no strange geometry at the edges of the rectangle, and the edges do not always coinside with tiles edges (see this for example:
http://b.tile.openstreetmap.org/18/190225/73869.png)

The problem affects a huge 2000x200km area, I have no idea what's causing it, guys at talk[at]openstreetmap.org suggested a bug report, which I'm filing now.

http://lists.openstreetmap.org/pipermail/talk/2013-March/066473.html

[openstreetmap-trac]

Author: pvm96[at]yandex.ru
[Added to the original trac issue at 3.23pm, Thursday, 14th March 2013]

There is a small discussion in talk maillist: http://lists.openstreetmap.org/pipermail/talk/2013-March/066462.html

[openstreetmap-trac]

Author: Ldp
[Added to the original trac issue at 2.16pm, Sunday, 24th March 2013]

I've seen strange effects like this in that area of the world before. It was a large pink-ish area then.

I notice it's not exactly on a tile boundary either:
http://b.tile.openstreetmap.org/18/190225/80172.png

I don't know what causes it. IIRC, it resolved itself spontaneously the last time it happened, a few years back.

[openstreetmap-trac]

Author: pnorman
[Added to the original trac issue at 2.33am, Sunday, 23rd February 2014]

wfm - and we've switched coastline sources now, so we'd need a new area to see if there's an issue again.

[openstreetmap-trac]

Author: pvm96[at]yandex.ru
[Added to the original trac issue at 3.39pm, Sunday, 23rd February 2014]

yep, it seems to be fine now.