https://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/The_Commissar_Vanishes_2.jpg/800px-The_Commissar_Vanishes_2.jpg

Error creating thumbnail: Image was not scaled, is the requested width bigger than the source?

That's weird. I tried to reproduce manually but couldn't:

tgr@terbium:~$ mwscript eval.php --wiki=commonswiki
> $img = wfLocalFile( 'Voroshilov,_Molotov,_Stalin,_with_Nikolai_Yezhov.jpg' );
> $params = array( 'width' => 800 );
> $thumbName = $img->thumbName( $params );
> $thumbPath = $img->getThumbPath( $thumbName );
> $mto = $img->transform( $params, File::RENDER_NOW );
> echo $mto->isError();
> echo $mto->hasFile();
1
> echo $mto->fileIsSource();

Both images were reuploaded a few hours age and the previous version was smaller than 800px, so this is some sort of metadata caching problem.

That's what I assumed (as the uploader). But it's strange, surely uploading larger versions is very much routine? Why would it break in this case but not usually?

Interestingly these specific files seem to be fixed now. I don't know how that happened, was it one of you?

The width/height cache for file metadata has an expiry date of 7 days. So its been long enough that the cache entry became expired.

Of course, the cache entry is supposed to be explicitly deleted upon a new version being uploaded. So the underlying cause may still be there

Given recent efforts to move to different levels of caches (e.g. WAN cache vs non-WAN cache), maybe there's something setting to one cache and reading from another. Or something like that. However grepping around there isn't really anything that sticks out.