It is possible that the hdf4 contains some code that overlaps the netcdf-c library. So yes, it is possible that --disable-netcdf removes that overlapping code. I have never investigated closely. I am not sure that adding the --enable-hdf4 option when building the netcdf-c library matters since you are never using libnetcdf to read an hdf4 file. =Dennis Heimbigner Unidata Ticket Details =================== Ticket ID: YFO-861586 Department: Support netCDF Priority: Normal Status: Closed =================== NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.