[gradsusr] Build GrADS 2.20 from Source, Errors with GRIB2 and gribmap

[Jennifer M Adams]

I have one more comment about the libpng error that appeared with gxprint. It’s helpful to track down these issues now, because when version 2.2.1 comes out, *all* the libraries will be dynamically linked, not just the graphics libs; it will be to know how to resolve the problems that will almost certainly arise. 

> >What was wrong with gxprint?
> 
> When trying to output a .png image I got the following warning with a blank image output.  Since I was linking the GrADS binaries with packages installed through zypper, perhaps it was a versioning problem.
> libpng warning: Application built with libpng-1.6.8 but running with 1.5.12

The png library is dynamically linked to the graphics plug-ins; my SUSE build used libpng-1.5, but maybe the default on your system is 1.6. Try using my executables with the local environment variable LD_LIBRARY_PATH pointing to your $SUPPLIBS/lib directory. Use ‘ldd’ to see what’s linked with the two gxpCairo.so files. 
—Jennifer

--
Jennifer Miletta Adams
Center for Ocean-Land-Atmosphere Studies (COLA)
George Mason University