Version 4.6.9 fixes a few issues has no new major features.
Most improvements relate to CDF5 handling and CMake builds.
Also, ncks now prints CDL by default.
I shelved my plans to skip 4.6.9 because we discovered a
consequential bug with the netCDF CDF5 implementation.
This led to a flurry of mini-features to diagnose and warn
users who might inadvertently stumble on corrupt CDF5 data.
Understanding the ramifications of this CDF5 bug is ongoing.
The best case scenario now, after a month of investigation,
is that Unidata will soon declare the bug solved and put the
appropriate patches in netCDF 4.5.0. We may make final
adjustments to diagnose/handle CDF5 issues based on those
patches, and release NCO 4.7.0 soon thereafter.