[ncl-talk] Segmentation fault on a GFS file fragment

[Peter Novak]

Dear NCL users and developers,
I encountered a segmentation fault of NCL on a GRIB2 file extracted from
NOAA GFS forecast datasets. The file is located here
http://www.aronde.net/dump/gfs.t18z.sfluxgrbf03.grib2PRES_TOP_high.grib2.

The file is extracted with curl from GFS dataset
http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.2015092918/gfs.t18z.sfluxgrbf03.grib2,
variable "PRES:high cloud top level" (as referred to in the index file
at http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.2015092918/gfs.t18z.sfluxgrbf03.grib2.idx).
The extraction command with ranges was:
$ curl -f -s -r 24660742-27538435 <url above> -o <outfile>

I am getting segfault upon the following:
$ ncl_filedump gfs.t18z.sfluxgrbf03.grib2PRES_TOP_high.grib2 -v PRES_P8_L233_GGA0_avg

The same when I try to read the file with an ncl script:
	indat=addfile(<file>, "r")
	vars=getfilevarnames(indat)
	printVarSummary(indat->$vars(0)$)

At the same time PanoplyJ reads the file without a hickup. Other files I
extracted using curl from the same GFS datasets work fine, the only
difference I spotted is that this one contains missing values (NaNf in
PanoplyJ), perhaps that could be the cause of the problem?

I would appreciate any advice regarding how to read and process this
file with NCL, or what is exactly wrong with it.

As for the NCL setup I have:
$ ncl
Copyright (C) 1995-2015 - All Rights Reserved
University Corporation for Atmospheric Research
NCAR Command Language Version 6.3.0
The use of this software is governed by a License Agreement.
See http://www.ncl.ucar.edu/ for more details.

$ uname -a 
Linux ... 3.16.0-38-generic #52~14.04.1-Ubuntu SMP Fri May 8 09:43:57 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Thanks for your help.

Best,

Peter.