Hi Tim, I think the problem is that the "-L/home3/twh142/netcdf_install/lib -lnetcdf" options must appear *after* the list of .o files on the gfortran command line. I think that was also the problem in the other email you allude to. The order of object files and libraries on the command line of compiler and linker invocations is important. Unresolved externals are only searched for in libraries mentioned after the object file that refers to them on the command line. --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: FTD-335729 Department: Support netCDF Priority: Normal Status: Closed