Added a comment block for future reference.

libdap2/CMakeLists.txt

@@ -6,6 +6,20 @@
 # See netcdf-c/COPYRIGHT file for more info.
 SET(dap2_SOURCES constraints.c dapcvt.c dapodom.c daputil.c ncdaperr.c cdf.c cache.c dapdump.c dapdebug.c dapattr.c ncd2dispatch.c getvara.c dceconstraints.c dcetab.c dceparse.c dcelex.c)
 
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
+set_property(SOURCE ncd2dispatch.c
+  PROPERTY
+    SKIP_UNITY_BUILD_INCLUSION ON)
+
+
 set_property(SOURCE ncd2dispatch.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

libdap4/CMakeLists.txt

@@ -6,6 +6,15 @@
 # See netcdf-c/COPYRIGHT file for more info.
 SET(dap4_SOURCES d4curlfunctions.c d4fix.c d4data.c d4file.c d4parser.c d4meta.c d4varx.c d4dump.c d4swap.c d4chunk.c d4printer.c d4read.c d4http.c d4util.c d4odom.c d4cvt.c d4debug.c ncd4dispatch.c)
 
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(SOURCE d4meta.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

libdispatch/CMakeLists.txt

@@ -8,6 +8,15 @@ SET(libdispatch_SOURCES dcopy.c dfile.c ddim.c datt.c dattinq.c dattput.c dattge
 daux.c dinstance.c dinstance_intern.c
 dcrc32.c dcrc32.h dcrc64.c ncexhash.c ncxcache.c ncjson.c ds3util.c dparallel.c dmissing.c)
 
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(SOURCE dinstance_intern.c dinstance.c dvarput.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

libsrc/CMakeLists.txt

@@ -4,6 +4,15 @@
 SET(libsrc_SOURCES v1hpg.c putget.c attr.c nc3dispatch.c
   nc3internal.c var.c dim.c ncx.c lookup3.c ncio.c)
 
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(SOURCE httpio.c posixio.c mmapio.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

nc_test/CMakeLists.txt

@@ -34,6 +34,16 @@ TARGET_LINK_LIBRARIES(nc_test
   netcdf
   ${HAVE_LIBM}
   )
+
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(TARGET nc_test PROPERTY UNITY_BUILD OFF)
 
 # Some extra stand-alone tests

ncdump/CMakeLists.txt

@@ -24,6 +24,15 @@ SET(ncpathcvt_FILES ncpathcvt.c ${XGETOPTSRC})
 SET(ncfilteravail_FILES ncfilteravail.c ${XGETOPTSRC})
 SET(nchdf5version_FILES nchdf5version.c)
  
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(SOURCE dumplib.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

ncgen/CMakeLists.txt

@@ -22,6 +22,15 @@ util.c bytebuffer.h data.h debug.h dump.h
 generate.h generr.h genlib.h includes.h list.h
 ncgen.h ncgeny.h util.h ${XGETOPTSRC})
 
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(SOURCE data.c
   PROPERTY
     SKIP_UNITY_BUILD_INCLUSION ON)

nctest/CMakeLists.txt

@@ -16,6 +16,16 @@ FILE(COPY ${COPY_FILES} DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/)
 ADD_EXECUTABLE(nctest ${nctest_SRC})
 TARGET_LINK_LIBRARIES(nctest netcdf)
 ADD_TEST(nctest ${EXECUTABLE_OUTPUT_PATH}/nctest)
+
+## 
+# Turn off inclusion of particular files when using the cmake-native
+# option to turn on Unity Builds.  
+#
+# For more information, see:
+#  * https://github.com/Unidata/netcdf-c/pull/2839/
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
+#  * https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD_MODE.html#prop_tgt:UNITY_BUILD_MODE
+##
 set_property(TARGET nctest PROPERTY UNITY_BUILD OFF)
 
 add_bin_test_no_prefix(tst_rename)