[QGIS-Developer] [QGIS-server] Messages: QNetworkDiskCache::prepare() unable to open temporary file

[Richard Duivenvoorde]

Hi,

I'm testing a QGISserver setup in which the project is cascading a WMTS 
(MapProxy).

Performance is not so good... so I fiddled with

QGIS_SERVER_CACHE_DIRECTORY=/cache
and even with ??
QGIS_OPTIONS_PATH=/cache

where /cache is a mounted internal cache dir

Is see QGISserver write all the stuff in /cache which I know from QGIS 
(profile dir) itself:

# from within the container:
# ls /cache
bookmarks.xml  data8  fonts  gdal_pam  oauth2-cache  palettes  prepared  
qgis-auth.db  qgis.db  symbology-style.db

But I keep seeing a lot of messages in the logs:
QNetworkDiskCache::prepare() unable to open temporary file
QNetworkDiskCache::prepare() unable to open temporary file
...

So my question is, WHERE does Qt try to create the network cache...

Thanks,

Richard Duivenvoorde