Hi Nyall, sorry, I've made it past this error -- did you see this post?
http://lists.osgeo.org/pipermail/qgis-user/2018-May/042461.html On 28.05.2018 07:07, Nyall Dawson wrote: > On 14 May 2018 at 19:30, Stephen <[email protected]> wrote: >> >> Automatically setting output paths to temporary files would be a >> sensible convenience, I think. >> >> In any event, I used processing.tools.system.getTempFilename() to set a >> filename and that gets me past the 'Incorrect parameter value for >> output' error. >> >> However, I am still getting "Unable to execute algorithm". >> >> In AlgorithmExecutor, line 55: >> results, ok = alg.run(parameters, context, feedback) >> >> returns ({}, False) >> >> parameters contains: >> >> {'GRASS_REGION_CELLSIZE_PARAMETER': 0.008333, 'use': 1, >> 'GRASS_REGION_PARAMETER': >> '33.91415594546105,41.91384412832699,-4.679722671256611,5.467319665842772', >> 'input': <qgis._core.QgsVectorLayer object at 0x7fdbbd02bc18>, >> 'GRASS_MIN_AREA_PARAMETER': 0.0001, 'GRASS_SNAP_TOLERANCE_PARAMETER': >> -1, 'type': 0, 'output': >> '/tmp/processing_da49d2e8c1bd4e249d1a5c6d42680149/5af9540a0b2212'} >> >> context contains: >> >> <qgis._core.QgsProcessingContext object at 0x7fdbbd04e3a8> >> >> and feedback contains: >> >> <qgis._core.QgsProcessingFeedback object at 0x7fdbbd02bee8> >> >> Without a useful error message, it's very difficult to troubleshoot this >> on my own. >> >> Do you have any idea what might be wrong here? > > I had another look at this. I suspect what might be happening is that > 'tmp/processing_da49d2e8c1bd4e249d1a5c6d42680149/5af9540a0b2212' does > not exist, which makes GRASS bomb out with a 'No such file or > directory' error. I have observed that sometimes, when using temp files generated by processing, QGIS (or the underlying algorithm) will not detect the file, even though it exists. I need to test this to confirm or falsify your theory. I'll let you know what I find. > Are you running this script from within QGIS itself? You should see > the detailed log, including all the output from grass, by opening the > log window and switching to the "Processing" tab (alternatively > running from a terminal window will also show this output on the > command line). Sadly, no, this is purely standalone code (the wisdom of this is arguable, but here we are). How can I turn on detailed logging in standalone PyQGIS? Thanks Stephen _______________________________________________ Qgis-user mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
