Merge pull request #431 from WardF/static-link-message.wif

Clarify message when failing with 'requires v4.7.4' error.

CMakeLists.txt

@@ -669,7 +669,12 @@ endif()
 
 CHECK_LIBRARY_EXISTS(${NETCDF_C_LIBRARY} nc_def_var_szip "" HAVE_DEF_VAR_SZIP)
 if (NOT HAVE_DEF_VAR_SZIP)
-  message(FATAL_ERROR "netcdf-c version 4.7.4 or greater is required, built with underlying szip support.")
+  message(FATAL_ERROR "netcdf-c version 4.7.4 or greater is required."
+                      "If netCDF-C 4.7.4 is present but is built statically, you *must* specify all dependencies"
+                      "by setting the LDFLAGS environmental variable.\n"
+                      "Example:\n"
+                      "    $ export LDFLAGS=$(nc-config --libs)"
+                      )
 endif()
 
 ###