When you build HDF4, you also get some HDF4-built versions of netCDF tools: ncdump and ncgen and the nctest test program.
Are these important to anyone? They are based on a very old version of netCDF (2.3.2, circa 1993) and conflict with netCDF’s own programs, which makes deploying netCDF and HDF4 together (unnecessarily?) complicated.
For 4.2.16, I’m adding a configure option to not build them and I’d like to have that disabled by default. In the future, I’d like to remove as much of this cruft as I can.