Re: 970212: netcdf2.4.3 build errors on SGI Challenge

>To: address@hidden
>From: "Neil R. Smith" <address@hidden>
>Subject: netcdf2.4.3 build errors on SGI Challenge
>Organization: Dept. Meteorology/Texas A&M University
>Keywords: 199702130028.RAA07186

Hi Neil,

You reported an error in the "make test" for ncdump in netCDF 2.4.3
under IRIX 6.2, with the symptoms:

> making `test' in directory /lite/bowman/lib/netcdf/netcdf-2.4.3/src/ncdump
> 
>       ../ncgen/ncgen -o test0.nc -n test0.cdl
>       ./ncdump test0.nc > test1.cdl
>       ../ncgen/ncgen -o test1.nc -n test1.cdl
>       ./ncdump -n test0 test1.nc > test2.cdl
> test1.cdl test2.cdl differ: char 987, line 69
> *** Error code 1 (bu21)

It turns out the error is in the4 ncgen utility, and is caused by a
compiler bug in the IRIX 6.2 C compiler, which we have reported to SGI.
A workaround is to interchange the order of lines 11 and 12 in
ncgen/generic.h, so that

union generic {                 /* used to hold any kind of fill_value */
    double doublev;
    float floatv;
    nclong longv;
    short shortv;
    char charv;
};

is changed to

union generic {                 /* used to hold any kind of fill_value */
    float floatv;
    double doublev;
    nclong longv;
    short shortv;
    char charv;
};

Then run "make all" in the ncgen directory to rebuild ncgen, after which
a "make test" from the top-level should get through the ncdump and ncgen
tests OK.

Alternatively, you can use the pre-release test version of netCDF-3
available from ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-3.3a.tar.Z
in which this workaround is already implemented, or wait until SGI
issues a fix for the compiler bug.

I've adding this to our "Known Problems with the netCDF Distribution"
document at
http://www.unidata.ucar.edu/staff/russ/netcdf/known_problems.html, until
we can get out a release that includes the workaround.

Thanks again for reporting the problem.

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu