Update CMake code to 3.18 minimum version (#2080)

* Update CMake code to 3.18 minimum version

* Updated release note

20 files changed, 117 insertions, 315 deletions

diff --git a/config/cmake/CTestScript.cmake b/config/cmake/CTestScript.cmake
index dcf2685..a2b122c 100644
--- a/config/cmake/CTestScript.cmake
+++ b/config/cmake/CTestScript.cmake
@@ -9,7 +9,7 @@
 # If you do not have access to either file, you may request a copy from
 # help@hdfgroup.org.
 #
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.18)
 ########################################################
 # For any comments please contact cdashhelp@hdfgroup.org
 #
diff --git a/config/cmake/ConfigureChecks.cmake b/config/cmake/ConfigureChecks.cmake
index d0de99b..d71ca08 100644
--- a/config/cmake/ConfigureChecks.cmake
+++ b/config/cmake/ConfigureChecks.cmake
@@ -187,9 +187,7 @@ macro (HDF_FUNCTION_TEST OTHER_TEST)
       )
     endif ()
 
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (TRACE "Performing ${OTHER_TEST}")
-    endif ()
+    message (TRACE "Performing ${OTHER_TEST}")
     try_compile (${OTHER_TEST}
         ${CMAKE_BINARY_DIR}
         ${HDF_RESOURCES_DIR}/HDFTests.c
@@ -199,13 +197,9 @@ macro (HDF_FUNCTION_TEST OTHER_TEST)
     )
     if (${OTHER_TEST})
       set (${HDF_PREFIX}_${OTHER_TEST} 1 CACHE INTERNAL "Other test ${FUNCTION}")
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Performing Other Test ${OTHER_TEST} - Success")
-      endif ()
+      message (VERBOSE "Performing Other Test ${OTHER_TEST} - Success")
     else ()
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Performing Other Test ${OTHER_TEST} - Failed")
-      endif ()
+      message (VERBOSE "Performing Other Test ${OTHER_TEST} - Failed")
       set (${HDF_PREFIX}_${OTHER_TEST} "" CACHE INTERNAL "Other test ${FUNCTION}")
       file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
           "Performing Other Test ${OTHER_TEST} failed with the following output:\n"
@@ -259,23 +253,17 @@ if (MINGW OR NOT WINDOWS)
           set (TEST_LFS_WORKS 1 CACHE INTERNAL ${msg})
           set (LARGEFILE 1)
           set (HDF_EXTRA_FLAGS ${HDF_EXTRA_FLAGS} -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE)
-          if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-            message (VERBOSE "${msg}... yes")
-          endif ()
+          message (VERBOSE "${msg}... yes")
         else ()
           set (TEST_LFS_WORKS "" CACHE INTERNAL ${msg})
-          if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-            message (VERBOSE "${msg}... no")
-          endif ()
+          message (VERBOSE "${msg}... no")
           file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
                 "Test TEST_LFS_WORKS Run failed with the following exit code:\n ${TEST_LFS_WORKS_RUN}\n"
           )
         endif ()
       else ()
         set (TEST_LFS_WORKS "" CACHE INTERNAL ${msg})
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-            message (VERBOSE "${msg}... no")
-        endif ()
+        message (VERBOSE "${msg}... no")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
             "Test TEST_LFS_WORKS Compile failed\n"
         )
@@ -308,15 +296,11 @@ endif ()
 macro (HDF_CHECK_TYPE_SIZE type var)
   set (aType ${type})
   set (aVar  ${var})
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (TRACE "Checking size of ${aType} and storing into ${aVar}")
-  endif ()
+  message (TRACE "Checking size of ${aType} and storing into ${aVar}")
   CHECK_TYPE_SIZE (${aType}   ${aVar})
   if (NOT ${aVar})
     set (${aVar} 0 CACHE INTERNAL "SizeOf for ${aType}")
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (TRACE "Size of ${aType} was NOT Found")
-    endif ()
+    message (TRACE "Size of ${aType} was NOT Found")
   endif ()
 endmacro ()
 
@@ -507,9 +491,7 @@ endif ()
 #-----------------------------------------------------------------------------
 if (WINDOWS)
   if (NOT HDF_NO_IOEO_TEST)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Checking for InitOnceExecuteOnce:")
-    endif ()
+    message (VERBOSE "Checking for InitOnceExecuteOnce:")
   if (NOT DEFINED ${HDF_PREFIX}_HAVE_IOEO)
     if (LARGEFILE)
       set (CMAKE_REQUIRED_DEFINITIONS
@@ -538,9 +520,7 @@ if (WINDOWS)
     # if the return value was 0 then it worked
     if ("${HAVE_IOEO_EXITCODE}" EQUAL 0)
       set (${HDF_PREFIX}_HAVE_IOEO 1 CACHE INTERNAL "Test InitOnceExecuteOnce")
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Performing Test InitOnceExecuteOnce - Success")
-      endif ()
+      message (VERBOSE "Performing Test InitOnceExecuteOnce - Success")
       file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
         "Performing C SOURCE FILE Test InitOnceExecuteOnce succeeded with the following output:\n"
         "${OUTPUT}\n"
@@ -552,9 +532,7 @@ if (WINDOWS)
         set (${HDF_PREFIX}_HAVE_IOEO "" CACHE INTERNAL "Test InitOnceExecuteOnce")
       endif ()
 
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Performing Test InitOnceExecuteOnce - Failed")
-      endif ()
+      message (VERBOSE "Performing Test InitOnceExecuteOnce - Failed")
       file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
         "Performing InitOnceExecuteOnce Test  failed with the following output:\n"
         "${OUTPUT}\n"
@@ -717,18 +695,14 @@ if (NOT WINDOWS)
         add_definitions ("-D_GNU_SOURCE")
       else ()
         set (TEST_DIRECT_VFD_WORKS "" CACHE INTERNAL ${msg})
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "${msg}... no")
-        endif ()
+        message (VERBOSE "${msg}... no")
         file (APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
               "Test TEST_DIRECT_VFD_WORKS Run failed with the following output and exit code:\n ${OUTPUT}\n"
         )
       endif ()
     else ()
       set (TEST_DIRECT_VFD_WORKS "" CACHE INTERNAL ${msg})
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "${msg}... no")
-      endif ()
+      message (VERBOSE "${msg}... no")
       file (APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
           "Test TEST_DIRECT_VFD_WORKS Compile failed with the following output:\n ${OUTPUT}\n"
       )
@@ -794,9 +768,7 @@ endif ()
 #-----------------------------------------------------------------------------
 set (RUN_OUTPUT_PATH_DEFAULT ${CMAKE_BINARY_DIR})
 macro (C_RUN FUNCTION_NAME SOURCE_CODE RETURN_VAR RETURN_OUTPUT_VAR)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Detecting C ${FUNCTION_NAME}")
-    endif ()
+    message (VERBOSE "Detecting C ${FUNCTION_NAME}")
     file (WRITE
         ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testCCompiler1.c
         ${SOURCE_CODE}
@@ -811,29 +783,23 @@ macro (C_RUN FUNCTION_NAME SOURCE_CODE RETURN_VAR RETURN_OUTPUT_VAR)
 
     set (${RETURN_OUTPUT_VAR} ${OUTPUT_VAR})
 
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
-      message (VERBOSE "Test COMPILE_RESULT_VAR ${COMPILE_RESULT_VAR} ")
-      message (VERBOSE "Test COMPILE_OUTPUT ${COMPILEOUT} ")
-      message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
-      message (VERBOSE "Test RUN_RESULT_VAR ${RUN_RESULT_VAR} ")
-      message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
-    endif ()
+    message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
+    message (VERBOSE "Test COMPILE_RESULT_VAR ${COMPILE_RESULT_VAR} ")
+    message (VERBOSE "Test COMPILE_OUTPUT ${COMPILEOUT} ")
+    message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
+    message (VERBOSE "Test RUN_RESULT_VAR ${RUN_RESULT_VAR} ")
+    message (VERBOSE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
 
     if (COMPILE_RESULT_VAR)
       if (RUN_RESULT_VAR EQUAL "0")
         set (${RETURN_VAR} 1 CACHE INTERNAL "Have C function ${FUNCTION_NAME}")
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Testing C ${FUNCTION_NAME} - OK")
-        endif ()
+        message (VERBOSE "Testing C ${FUNCTION_NAME} - OK")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
             "Determining if the C ${FUNCTION_NAME} exists passed with the following output:\n"
             "${OUTPUT_VAR}\n\n"
         )
       else ()
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Testing C ${FUNCTION_NAME} - Fail")
-        endif ()
+        message (VERBOSE "Testing C ${FUNCTION_NAME} - Fail")
         set (${RETURN_VAR} 0 CACHE INTERNAL "Have C function ${FUNCTION_NAME}")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
             "Determining if the C ${FUNCTION_NAME} exists failed with the following output:\n"
@@ -906,23 +872,17 @@ macro (H5ConversionTests TEST msg)
     if (${TEST}_COMPILE)
       if (${TEST}_RUN EQUAL "0")
         set (${TEST} 1 CACHE INTERNAL ${msg})
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "${msg}... yes")
-        endif ()
+        message (VERBOSE "${msg}... yes")
       else ()
         set (${TEST} "" CACHE INTERNAL ${msg})
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "${msg}... no")
-        endif ()
+        message (VERBOSE "${msg}... no")
         file (APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
               "Test ${TEST} Run failed with the following output and exit code:\n ${OUTPUT}\n"
         )
       endif ()
     else ()
       set (${TEST} "" CACHE INTERNAL ${msg})
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "${msg}... no")
-      endif ()
+      message (VERBOSE "${msg}... no")
       file (APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
           "Test ${TEST} Compile failed with the following output:\n ${OUTPUT}\n"
       )
diff --git a/config/cmake/FindMFU.cmake b/config/cmake/FindMFU.cmake
index 37699e2..2a4278a 100644
--- a/config/cmake/FindMFU.cmake
+++ b/config/cmake/FindMFU.cmake
@@ -89,9 +89,7 @@ if (NOT MFU_FOUND)
       "Mfu was not found. Make sure MFU_LIBRARY and MFU_INCLUDE_DIR are set or set the MFU_INSTALL environment variable."
   )
   if (NOT MFU_FIND_QUIETLY)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "${MFU_DIR_MESSAGE}")
-    endif ()
+    message (VERBOSE "${MFU_DIR_MESSAGE}")
   else ()
     if (MFU_FIND_REQUIRED)
       message (FATAL_ERROR "Mfu was NOT found and is Required by this project")
diff --git a/config/cmake/FindSZIP.cmake b/config/cmake/FindSZIP.cmake
index 846a3d1..b96a732 100644
--- a/config/cmake/FindSZIP.cmake
+++ b/config/cmake/FindSZIP.cmake
@@ -118,9 +118,7 @@ if (NOT SZIP_FOUND)
       "SZip was not found. Make sure SZIP_LIBRARY and SZIP_INCLUDE_DIR are set or set the SZIP_INSTALL environment variable."
   )
   if (NOT SZIP_FIND_QUIETLY)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "${SZIP_DIR_MESSAGE}")
-    endif ()
+    message (VERBOSE "${SZIP_DIR_MESSAGE}")
   else ()
     if (SZIP_FIND_REQUIRED)
       message (FATAL_ERROR "SZip was NOT found and is Required by this project")
diff --git a/config/cmake/HDF5PluginMacros.cmake b/config/cmake/HDF5PluginMacros.cmake
index 53afe1a..ba1f56f 100644
--- a/config/cmake/HDF5PluginMacros.cmake
+++ b/config/cmake/HDF5PluginMacros.cmake
@@ -14,9 +14,7 @@ macro (EXTERNAL_PLUGIN_LIBRARY compress_type)
     )
   endif ()
   FetchContent_GetProperties(PLUGIN)
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "HDF5_INCLUDE_DIR=${HDF5_INCLUDE_DIR}")
-  endif ()
+  message (VERBOSE "HDF5_INCLUDE_DIR=${HDF5_INCLUDE_DIR}")
   if(NOT PLUGIN_POPULATED)
     FetchContent_Populate(PLUGIN)
     include (${HDF_RESOURCES_DIR}/HDF5PluginCache.cmake)
@@ -68,9 +66,7 @@ macro (EXTERNAL_PLUGIN_LIBRARY compress_type)
       target_include_directories (h5ex_d_zfp PRIVATE "${HDF5_SRC_INCLUDE_DIRS};${HDF5_SRC_BINARY_DIR}")
     endif ()
   endif ()
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "HDF5_INCLUDE_DIR=${HDF5_INCLUDE_DIR}")
-  endif ()
+  message (VERBOSE "HDF5_INCLUDE_DIR=${HDF5_INCLUDE_DIR}")
   set (PLUGIN_BINARY_DIR "${plugin_BINARY_DIR}")
   set (PLUGIN_SOURCE_DIR "${plugin_SOURCE_DIR}")
   set (PLUGIN_LIBRARY "PLUGIN")
diff --git a/config/cmake/HDF5UseFortran.cmake b/config/cmake/HDF5UseFortran.cmake
index 43e006c..79084cb 100644
--- a/config/cmake/HDF5UseFortran.cmake
+++ b/config/cmake/HDF5UseFortran.cmake
@@ -19,10 +19,8 @@ enable_language (Fortran)
 set (HDF_PREFIX "H5")
 include (CheckFortranFunctionExists)
 
-if (NOT CMAKE_VERSION VERSION_LESS "3.14.0")
-  include (CheckFortranSourceRuns)
-  include (CheckFortranSourceCompiles)
-endif ()
+include (CheckFortranSourceRuns)
+include (CheckFortranSourceCompiles)
 
 # Read source line beginning at the line matching Input:"START" and ending at the line matching Input:"END"
 macro (READ_SOURCE SOURCE_START SOURCE_END RETURN_VAR)
@@ -36,9 +34,7 @@ set (RUN_OUTPUT_PATH_DEFAULT ${CMAKE_BINARY_DIR})
 # so this one is used.
 #-----------------------------------------------------------------------------
 macro (FORTRAN_RUN FUNCTION_NAME SOURCE_CODE RUN_RESULT_VAR1 COMPILE_RESULT_VAR1 RETURN_VAR RETURN_OUTPUT_VAR)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Detecting Fortran ${FUNCTION_NAME}")
-    endif ()
+    message (VERBOSE "Detecting Fortran ${FUNCTION_NAME}")
     file (WRITE
         ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testFortranCompiler1.f90
         "${SOURCE_CODE}"
@@ -54,24 +50,18 @@ macro (FORTRAN_RUN FUNCTION_NAME SOURCE_CODE RUN_RESULT_VAR1 COMPILE_RESULT_VAR1
     if (${COMPILE_RESULT_VAR})
       set(${RETURN_VAR} ${RUN_RESULT_VAR})
       if (${RUN_RESULT_VAR} MATCHES 0)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Testing Fortran ${FUNCTION_NAME} - OK")
-        endif ()
+        message (VERBOSE "Testing Fortran ${FUNCTION_NAME} - OK")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
             "Determining if the Fortran ${FUNCTION_NAME} exists passed\n"
         )
       else ()
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Testing Fortran ${FUNCTION_NAME} - Fail")
-        endif ()
+        message (VERBOSE "Testing Fortran ${FUNCTION_NAME} - Fail")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
             "Determining if the Fortran ${FUNCTION_NAME} exists failed: ${RUN_RESULT_VAR}\n"
         )
       endif ()
     else ()
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Compiling Fortran ${FUNCTION_NAME} - Fail")
-        endif ()
+        message (VERBOSE "Compiling Fortran ${FUNCTION_NAME} - Fail")
         file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
             "Determining if the Fortran ${FUNCTION_NAME} compiles failed: ${COMPILE_RESULT_VAR}\n"
         )
@@ -82,11 +72,7 @@ endmacro ()
 #  Check to see C_LONG_DOUBLE is available
 
 READ_SOURCE("PROGRAM PROG_FC_HAVE_C_LONG_DOUBLE" "END PROGRAM PROG_FC_HAVE_C_LONG_DOUBLE" SOURCE_CODE)
-if (NOT CMAKE_VERSION VERSION_LESS "3.14.0")
-  check_fortran_source_compiles (${SOURCE_CODE} FORTRAN_HAVE_C_LONG_DOUBLE SRC_EXT f90)
-else ()
-  CHECK_FORTRAN_FEATURE(c_long_double "${SOURCE_CODE}" FORTRAN_HAVE_C_LONG_DOUBLE)
-endif ()
+check_fortran_source_compiles (${SOURCE_CODE} FORTRAN_HAVE_C_LONG_DOUBLE SRC_EXT f90)
 
 if (${FORTRAN_HAVE_C_LONG_DOUBLE})
   set (${HDF_PREFIX}_FORTRAN_HAVE_C_LONG_DOUBLE 1)
@@ -97,11 +83,7 @@ endif ()
 # Check to see C_LONG_DOUBLE is different from C_DOUBLE
 
 READ_SOURCE("MODULE type_mod" "END PROGRAM PROG_FC_C_LONG_DOUBLE_EQ_C_DOUBLE" SOURCE_CODE)
-if (NOT CMAKE_VERSION VERSION_LESS "3.14.0")
-  check_fortran_source_compiles (${SOURCE_CODE} FORTRAN_C_LONG_DOUBLE_IS_UNIQUE SRC_EXT f90)
-else ()
-  CHECK_FORTRAN_FEATURE(c_long_double "${SOURCE_CODE}" FORTRAN_C_LONG_DOUBLE_IS_UNIQUE)
-endif ()
+check_fortran_source_compiles (${SOURCE_CODE} FORTRAN_C_LONG_DOUBLE_IS_UNIQUE SRC_EXT f90)
 if (${FORTRAN_C_LONG_DOUBLE_IS_UNIQUE})
   set (${HDF_PREFIX}_FORTRAN_C_LONG_DOUBLE_IS_UNIQUE 1)
 else ()
@@ -212,9 +194,7 @@ string (REGEX REPLACE " " "" pack_int_sizeof "${pack_int_sizeof}")
 
 set (PAC_FC_ALL_INTEGER_KINDS_SIZEOF "\{${pack_int_sizeof}\}")
 
-if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-  message (VERBOSE "....FOUND SIZEOF for INTEGER KINDs ${PAC_FC_ALL_INTEGER_KINDS_SIZEOF}")
-endif ()
+message (VERBOSE "....FOUND SIZEOF for INTEGER KINDs ${PAC_FC_ALL_INTEGER_KINDS_SIZEOF}")
 # **********
 # REALS
 # **********
diff --git a/config/cmake/HDF5_Examples.cmake.in b/config/cmake/HDF5_Examples.cmake.in
index 23c07e8..43e9ea3 100644
--- a/config/cmake/HDF5_Examples.cmake.in
+++ b/config/cmake/HDF5_Examples.cmake.in
@@ -9,7 +9,7 @@
 # If you do not have access to either file, you may request a copy from
 # help@hdfgroup.org.
 #
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.18)
 ###############################################################################################################
 # This script will build and run the examples from a folder
 # Execute from a command line:
diff --git a/config/cmake/HDFCXXCompilerFlags.cmake b/config/cmake/HDFCXXCompilerFlags.cmake
index e654db3..b1e4b3c 100644
--- a/config/cmake/HDFCXXCompilerFlags.cmake
+++ b/config/cmake/HDFCXXCompilerFlags.cmake
@@ -17,9 +17,7 @@ set (CMAKE_CXX_STANDARD_REQUIRED TRUE)
 set (CMAKE_CXX_EXTENSIONS OFF)
 
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_SANITIZER_FLAGS} ${CMAKE_CXX_FLAGS}")
-if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-  message (VERBOSE "Warnings Configuration: CXX default: ${CMAKE_CXX_FLAGS}")
-endif ()
+message (VERBOSE "Warnings Configuration: CXX default: ${CMAKE_CXX_FLAGS}")
 #-----------------------------------------------------------------------------
 # Compiler specific flags : Shouldn't there be compiler tests for these
 #-----------------------------------------------------------------------------
@@ -140,9 +138,7 @@ else ()
   elseif (CMAKE_CXX_COMPILER_ID STREQUAL "PGI")
     list (APPEND HDF5_CMAKE_CXX_FLAGS "-Minform=inform")
   endif ()
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "CMAKE_CXX_FLAGS_GENERAL=${HDF5_CMAKE_CXX_FLAGS}")
-  endif ()
+  message (VERBOSE "CMAKE_CXX_FLAGS_GENERAL=${HDF5_CMAKE_CXX_FLAGS}")
 endif ()
 
 #-----------------------------------------------------------------------------
diff --git a/config/cmake/HDFCompilerFlags.cmake b/config/cmake/HDFCompilerFlags.cmake
index 3a0a590..504c163 100644
--- a/config/cmake/HDFCompilerFlags.cmake
+++ b/config/cmake/HDFCompilerFlags.cmake
@@ -14,9 +14,7 @@ set(CMAKE_C_STANDARD_REQUIRED TRUE)
 
 set (CMAKE_C_FLAGS "${CMAKE_C99_STANDARD_COMPILE_OPTION} ${CMAKE_C_FLAGS}")
 set (CMAKE_C_FLAGS "${CMAKE_C_SANITIZER_FLAGS} ${CMAKE_C_FLAGS}")
-if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-  message (VERBOSE "Warnings Configuration: C default: ${CMAKE_C_FLAGS}")
-endif ()
+message (VERBOSE "Warnings Configuration: C default: ${CMAKE_C_FLAGS}")
 #-----------------------------------------------------------------------------
 # Compiler specific flags : Shouldn't there be compiler tests for these
 #-----------------------------------------------------------------------------
@@ -163,9 +161,7 @@ else ()
   elseif (CMAKE_C_COMPILER_ID STREQUAL "PGI")
     list (APPEND HDF5_CMAKE_C_FLAGS "-Minform=inform")
   endif ()
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "CMAKE_C_FLAGS_GENERAL=${HDF5_CMAKE_C_FLAGS}")
-  endif ()
+  message (VERBOSE "CMAKE_C_FLAGS_GENERAL=${HDF5_CMAKE_C_FLAGS}")
 endif ()
 
 #-----------------------------------------------------------------------------
diff --git a/config/cmake/HDFFortranCompilerFlags.cmake b/config/cmake/HDFFortranCompilerFlags.cmake
index 7fdc3f8..108a4e9 100644
--- a/config/cmake/HDFFortranCompilerFlags.cmake
+++ b/config/cmake/HDFFortranCompilerFlags.cmake
@@ -10,9 +10,7 @@
 # help@hdfgroup.org.
 #
 
-if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-  message (VERBOSE "Warnings Configuration: default Fortran: ${CMAKE_Fortran_FLAGS}")
-endif ()
+message (VERBOSE "Warnings Configuration: default Fortran: ${CMAKE_Fortran_FLAGS}")
 
 #-----------------------------------------------------------------------------
 # Option to allow the user to disable compiler warnings
@@ -75,9 +73,7 @@ if (NOT MSVC AND NOT MINGW)
   elseif (CMAKE_Fortran_COMPILER_ID STREQUAL "PGI")
     list (APPEND HDF5_CMAKE_Fortran_FLAGS "-Mfreeform" "-Mdclchk" "-Mstandard" "-Mallocatable=03")
   endif ()
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "HDF5_CMAKE_Fortran_FLAGS=${HDF5_CMAKE_Fortran_FLAGS}")
-  endif ()
+  message (VERBOSE "HDF5_CMAKE_Fortran_FLAGS=${HDF5_CMAKE_Fortran_FLAGS}")
 
   if (CMAKE_Fortran_COMPILER_ID STREQUAL "GNU")
     # Append more extra warning flags that only gcc 4.8+ knows about
diff --git a/config/cmake/HDFMacros.cmake b/config/cmake/HDFMacros.cmake
index 9d98408..f91c537 100644
--- a/config/cmake/HDFMacros.cmake
+++ b/config/cmake/HDFMacros.cmake
@@ -28,9 +28,7 @@ macro (SET_HDF_BUILD_TYPE)
     endif()
   endif()
   if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Setting build type to 'RelWithDebInfo' as none was specified.")
-    endif()
+    message (VERBOSE "Setting build type to 'RelWithDebInfo' as none was specified.")
     set(CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "Choose the type of build." FORCE)
     # Set the possible values of build type for cmake-gui
     set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
@@ -448,19 +446,6 @@ macro (HDF_DIR_PATHS package_prefix)
       set (CMAKE_GENERIC_PROGRAM_FILES)
     endif ()
   endif ()
-
-#-----------------------------------------------------------------------------
-# Setup pre-3.14 FetchContent
-#-----------------------------------------------------------------------------
-  if(${CMAKE_VERSION} VERSION_LESS 3.14)
-    macro(FetchContent_MakeAvailable NAME)
-        FetchContent_GetProperties(${NAME})
-        if(NOT ${NAME}_POPULATED)
-            FetchContent_Populate(${NAME})
-            add_subdirectory(${${NAME}_SOURCE_DIR} ${${NAME}_BINARY_DIR})
-        endif()
-    endmacro()
-  endif()
 endmacro ()
 
 macro (ADD_H5_FLAGS h5_flag_var infile)
diff --git a/config/cmake/HDFUseFortran.cmake b/config/cmake/HDFUseFortran.cmake
index c96298f..61adffd 100644
--- a/config/cmake/HDFUseFortran.cmake
+++ b/config/cmake/HDFUseFortran.cmake
@@ -16,10 +16,8 @@
 enable_language (Fortran)
 set (HDF_PREFIX "H5")
 
-if (NOT CMAKE_VERSION VERSION_LESS "3.14.0")
-  include (CheckFortranSourceRuns)
-  include (CheckFortranSourceCompiles)
-endif ()
+include (CheckFortranSourceRuns)
+include (CheckFortranSourceCompiles)
 
 #-------------------------------------------------------------------------------
 #  Fix Fortran flags if we are compiling statically on Windows using
@@ -119,98 +117,15 @@ set (ISO_C_BINDING_CODE
   "
 )
 
-if (NOT CMAKE_VERSION VERSION_LESS "3.14.0")
-  if (HDF5_REQUIRED_LIBRARIES)
-    set (CMAKE_REQUIRED_LIBRARIES "${HDF5_REQUIRED_LIBRARIES}")
-  endif ()
-  check_fortran_source_compiles (${SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_SIZEOF SRC_EXT f90)
-  check_fortran_source_compiles (${C_SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_C_SIZEOF SRC_EXT f90)
-  check_fortran_source_compiles (${STORAGE_SIZE_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_STORAGE_SIZE SRC_EXT f90)
-  check_fortran_source_compiles (${ISO_FORTRAN_ENV_CODE} ${HDF_PREFIX}_HAVE_ISO_FORTRAN_ENV SRC_EXT f90)
-  check_fortran_source_compiles (${REALISNOTDOUBLE_CODE} ${HDF_PREFIX}_FORTRAN_DEFAULT_REAL_NOT_DOUBLE SRC_EXT f90)
-  check_fortran_source_compiles (${ISO_C_BINDING_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_ISO_C_BINDING SRC_EXT f90)
-else ()
-  #-----------------------------------------------------------------------------
-  # The provided CMake Fortran macros don't provide a general check function
-  # so this one is used for a sizeof test.
-  #-----------------------------------------------------------------------------
-  macro (CHECK_FORTRAN_FEATURE FUNCTION CODE VARIABLE)
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Testing Fortran ${FUNCTION}")
-      endif ()
-      if (HDF5_REQUIRED_LIBRARIES)
-        set (CHECK_FUNCTION_EXISTS_ADD_LIBRARIES
-            "-DLINK_LIBRARIES:STRING=${HDF5_REQUIRED_LIBRARIES}")
-      else ()
-        set (CHECK_FUNCTION_EXISTS_ADD_LIBRARIES)
-      endif ()
-      file (WRITE
-          ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testFortranCompiler.f90
-          "${CODE}"
-      )
-      TRY_COMPILE (RESULT_VAR
-          ${CMAKE_BINARY_DIR}
-          ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testFortranCompiler.f90
-          CMAKE_FLAGS "${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}"
-          OUTPUT_VARIABLE OUTPUT
-      )
-
-  #    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-  #      message (TRACE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
-  #      message (TRACE "Test result ${OUTPUT}")
-  #      message (TRACE "* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ")
-  #    endif ()
-
-      if (${RESULT_VAR})
-        set (${VARIABLE} 1 CACHE INTERNAL "Have Fortran function ${FUNCTION}")
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Testing Fortran ${FUNCTION} - OK")
-        endif ()
-        file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
-            "Determining if the Fortran ${FUNCTION} exists passed with the following output:\n"
-            "${OUTPUT}\n\n"
-        )
-      else ()
-        message (STATUS "Testing Fortran ${FUNCTION} - Fail")
-        set (${VARIABLE} 0 CACHE INTERNAL "Have Fortran function ${FUNCTION}")
-        file (APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
-            "Determining if the Fortran ${FUNCTION} exists failed with the following output:\n"
-            "${OUTPUT}\n\n")
-      endif ()
-  endmacro ()
-
-  #-----------------------------------------------------------------------------
-  # Configure Checks which require Fortran compilation must go in here
-  # not in the main ConfigureChecks.cmake files, because if the user has
-  # no Fortran compiler, problems arise.
-  #
-  # Be careful with leading spaces here, do not remove them.
-  #-----------------------------------------------------------------------------
-
-  # Check for Non-standard extension intrinsic function SIZEOF
-  set (${HDF_PREFIX}_FORTRAN_HAVE_SIZEOF FALSE)
-  CHECK_FORTRAN_FEATURE(sizeof_code ${SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_SIZEOF)
-
-  # Check for F2008 standard intrinsic function C_SIZEOF
-  set (${HDF_PREFIX}_FORTRAN_HAVE_C_SIZEOF FALSE)
-  CHECK_FORTRAN_FEATURE(c_sizeof_code ${C_SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_C_SIZEOF)
-
-  # Check for F2008 standard intrinsic function STORAGE_SIZE
-  CHECK_FORTRAN_FEATURE(storage_size_code ${STORAGE_SIZE_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_STORAGE_SIZE)
-
-  # Check for F2008 standard intrinsic module "ISO_FORTRAN_ENV"
-  set (${HDF_PREFIX}_HAVE_ISO_FORTRAN_ENV FALSE)
-  CHECK_FORTRAN_FEATURE(iso_fortran_env_code ${ISO_FORTRAN_ENV_CODE} ${HDF_PREFIX}_HAVE_ISO_FORTRAN_ENV)
-
-  set (${HDF_PREFIX}_FORTRAN_DEFAULT_REAL_NOT_DOUBLE FALSE)
-  CHECK_FORTRAN_FEATURE(realisnotdouble_code ${REALISNOTDOUBLE_CODE} ${HDF_PREFIX}_FORTRAN_DEFAULT_REAL_NOT_DOUBLE)
-
-  #-----------------------------------------------------------------------------
-  # Checks if the ISO_C_BINDING module meets all the requirements
-  #-----------------------------------------------------------------------------
-  set (${HDF_PREFIX}_FORTRAN_HAVE_ISO_C_BINDING FALSE)
-  CHECK_FORTRAN_FEATURE(iso_c_binding_code ${ISO_C_BINDING_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_ISO_C_BINDING)
+if (HDF5_REQUIRED_LIBRARIES)
+  set (CMAKE_REQUIRED_LIBRARIES "${HDF5_REQUIRED_LIBRARIES}")
 endif ()
+check_fortran_source_compiles (${SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_SIZEOF SRC_EXT f90)
+check_fortran_source_compiles (${C_SIZEOF_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_C_SIZEOF SRC_EXT f90)
+check_fortran_source_compiles (${STORAGE_SIZE_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_STORAGE_SIZE SRC_EXT f90)
+check_fortran_source_compiles (${ISO_FORTRAN_ENV_CODE} ${HDF_PREFIX}_HAVE_ISO_FORTRAN_ENV SRC_EXT f90)
+check_fortran_source_compiles (${REALISNOTDOUBLE_CODE} ${HDF_PREFIX}_FORTRAN_DEFAULT_REAL_NOT_DOUBLE SRC_EXT f90)
+check_fortran_source_compiles (${ISO_C_BINDING_CODE} ${HDF_PREFIX}_FORTRAN_HAVE_ISO_C_BINDING SRC_EXT f90)
 
 #-----------------------------------------------------------------------------
 # Add debug information (intel Fortran : JB)
diff --git a/config/cmake/fileCompareTest.cmake b/config/cmake/fileCompareTest.cmake
index 4a8dc09..18a29d9 100644
--- a/config/cmake/fileCompareTest.cmake
+++ b/config/cmake/fileCompareTest.cmake
@@ -46,66 +46,50 @@ if (TEST_STRINGS STREQUAL "YES")
 
   # now compare the outputs
   execute_process (
-      COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_ONEFILE} ${TEST_FOLDER}/${TEST_TWOFILE}
+      COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_ONEFILE} ${TEST_FOLDER}/${TEST_TWOFILE}
       RESULT_VARIABLE TEST_RESULT
   )
 
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "COMPARE Result: ${TEST_RESULT}: ${TEST_STRING_SIZE}=${TEST_U_STRING_LEN}-${TEST_O_STRING_LEN}")
-  endif ()
+  message (VERBOSE "COMPARE Result: ${TEST_RESULT}: ${TEST_STRING_SIZE}=${TEST_U_STRING_LEN}-${TEST_O_STRING_LEN}")
   # if the return value is !=${TEST_EXPECT} bail out
   if (NOT TEST_RESULT EQUAL TEST_EXPECT)
     message (FATAL_ERROR "Failed: The output of ${TEST_FOLDER}/${TEST_ONEFILE} did not match ${TEST_FOLDER}/${TEST_TWOFILE}.\n${TEST_ERROR}")
   endif ()
 else ()
-  if (CMAKE_VERSION VERSION_LESS "3.14.0")
-    message (FATAL_ERROR "CANNOT get file size, file command SIZE not supported")
-  else ()
-    file (SIZE ${TEST_FOLDER}/${TEST_ONEFILE} TEST_ONE_SIZE)
-    file (SIZE ${TEST_FOLDER}/${TEST_TWOFILE} TEST_TWO_SIZE)
-    if (TEST_FUNCTION MATCHES "LT")
-      if (TEST_ONE_SIZE LESS TEST_TWO_SIZE)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was less ${TEST_FOLDER}/${TEST_TWOFILE}")
-        endif ()
-      else ()
-        message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT less ${TEST_FOLDER}/${TEST_TWOFILE}")
-      endif ()
-    elseif (TEST_FUNCTION MATCHES "LTEQ")
-      if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSES "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was less or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-        endif ()
-      else ()
-        message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT less or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-      endif ()
-    elseif (TEST_FUNCTION MATCHES "EQ")
-      if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-        endif ()
-      else ()
-        message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-      endif ()
-    elseif (TEST_FUNCTION MATCHES "GTEQ")
-      if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was greater or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-        endif ()
-      else ()
-        message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT greater or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
-      endif ()
-    elseif (TEST_FUNCTION MATCHES "GT")
-      if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
-        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-          message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was greater ${TEST_FOLDER}/${TEST_TWOFILE}")
-        endif ()
-      else ()
-        message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT greater ${TEST_FOLDER}/${TEST_TWOFILE}")
-      endif ()
+  file (SIZE ${TEST_FOLDER}/${TEST_ONEFILE} TEST_ONE_SIZE)
+  file (SIZE ${TEST_FOLDER}/${TEST_TWOFILE} TEST_TWO_SIZE)
+  if (TEST_FUNCTION MATCHES "LT")
+    if (TEST_ONE_SIZE LESS TEST_TWO_SIZE)
+      message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was less ${TEST_FOLDER}/${TEST_TWOFILE}")
+    else ()
+      message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT less ${TEST_FOLDER}/${TEST_TWOFILE}")
+    endif ()
+  elseif (TEST_FUNCTION MATCHES "LTEQ")
+    if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
+      message (VERBOSES "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was less or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
+    else ()
+      message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT less or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
+    endif ()
+  elseif (TEST_FUNCTION MATCHES "EQ")
+    if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
+      message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was equal ${TEST_FOLDER}/${TEST_TWOFILE}")
     else ()
-      message (FATAL_ERROR "Failed: Incorrect test size compare command provided.\n${TEST_ERROR}")
+      message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT equal ${TEST_FOLDER}/${TEST_TWOFILE}")
     endif ()
+  elseif (TEST_FUNCTION MATCHES "GTEQ")
+    if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
+      message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was greater or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
+    else ()
+      message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT greater or equal ${TEST_FOLDER}/${TEST_TWOFILE}")
+    endif ()
+  elseif (TEST_FUNCTION MATCHES "GT")
+    if (TEST_ONE_SIZE LESS_EQUAL TEST_TWO_SIZE)
+      message (VERBOSE "Passed: The size of ${TEST_FOLDER}/${TEST_ONEFILE} was greater ${TEST_FOLDER}/${TEST_TWOFILE}")
+    else ()
+      message (FATAL_ERROR "The size of ${TEST_FOLDER}/${TEST_ONEFILE} was NOT greater ${TEST_FOLDER}/${TEST_TWOFILE}")
+    endif ()
+  else ()
+    message (FATAL_ERROR "Failed: Incorrect test size compare command provided.\n${TEST_ERROR}")
   endif ()
 endif ()
 
diff --git a/config/cmake/grepTest.cmake b/config/cmake/grepTest.cmake
index 3b0baf5..9e80956 100644
--- a/config/cmake/grepTest.cmake
+++ b/config/cmake/grepTest.cmake
@@ -49,9 +49,7 @@ endif ()
 
 if (TEST_ENV_VAR)
   set (ENV{${TEST_ENV_VAR}} "${TEST_ENV_VALUE}")
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (TRACE "ENV:${TEST_ENV_VAR}=$ENV{${TEST_ENV_VAR}}")
-  endif ()
+  message (TRACE "ENV:${TEST_ENV_VAR}=$ENV{${TEST_ENV_VAR}}")
 endif ()
 
 # run the test program, capture the stdout/stderr and the result var
@@ -112,7 +110,7 @@ if (TEST_ERRREF)
         if (NOT TEST_SORT_COMPARE)
           # now compare the output with the reference
           execute_process (
-              COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
+              COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
               RESULT_VARIABLE TEST_COMPARE_RESULT
           )
         else ()
diff --git a/config/cmake/jrunTest.cmake b/config/cmake/jrunTest.cmake
index be856c5..21183af 100644
--- a/config/cmake/jrunTest.cmake
+++ b/config/cmake/jrunTest.cmake
@@ -148,7 +148,7 @@ if (NOT TEST_SKIP_COMPARE)
       if (NOT TEST_SORT_COMPARE)
         # now compare the output with the reference
         execute_process (
-            COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
+            COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
             RESULT_VARIABLE TEST_COMPARE_RESULT
         )
       else ()
@@ -218,7 +218,7 @@ if (NOT TEST_SKIP_COMPARE)
 
       # now compare the error output with the error reference
       execute_process (
-          COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_OUTPUT}.err ${TEST_FOLDER}/${TEST_ERRREF}
+          COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_OUTPUT}.err ${TEST_FOLDER}/${TEST_ERRREF}
           RESULT_VARIABLE TEST_ERRREF_RESULT
       )
       if (TEST_ERRREF_RESULT)
diff --git a/config/cmake/runTest.cmake b/config/cmake/runTest.cmake
index ad72a9e..12b4818 100644
--- a/config/cmake/runTest.cmake
+++ b/config/cmake/runTest.cmake
@@ -212,19 +212,19 @@ if (NOT TEST_SKIP_COMPARE)
     file (READ ${TEST_FOLDER}/${TEST_REFERENCE} TEST_STREAM)
     list (LENGTH TEST_STREAM test_len)
     if (test_len GREATER 0)
-      if (WIN32)
-        configure_file(${TEST_FOLDER}/${TEST_REFERENCE} ${TEST_FOLDER}/${TEST_REFERENCE}.tmp NEWLINE_STYLE CRLF)
-        if (EXISTS "${TEST_FOLDER}/${TEST_REFERENCE}.tmp")
-          file(RENAME ${TEST_FOLDER}/${TEST_REFERENCE}.tmp ${TEST_FOLDER}/${TEST_REFERENCE})
-        endif ()
-        #file (READ ${TEST_FOLDER}/${TEST_REFERENCE} TEST_STREAM)
-        #file (WRITE ${TEST_FOLDER}/${TEST_REFERENCE} "${TEST_STREAM}")
-      endif ()
+    #  if (WIN32) # no longer needed for CMake > 3.15
+    #    configure_file(${TEST_FOLDER}/${TEST_REFERENCE} ${TEST_FOLDER}/${TEST_REFERENCE}.tmp NEWLINE_STYLE CRLF)
+    #    if (EXISTS "${TEST_FOLDER}/${TEST_REFERENCE}.tmp")
+    #      file(RENAME ${TEST_FOLDER}/${TEST_REFERENCE}.tmp ${TEST_FOLDER}/${TEST_REFERENCE})
+    #    endif ()
+    #    #file (READ ${TEST_FOLDER}/${TEST_REFERENCE} TEST_STREAM)
+    #    #file (WRITE ${TEST_FOLDER}/${TEST_REFERENCE} "${TEST_STREAM}")
+    #  endif ()
 
       if (NOT TEST_SORT_COMPARE)
         # now compare the output with the reference
         execute_process (
-            COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
+            COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_FOLDER}/${TEST_REFERENCE}
             RESULT_VARIABLE TEST_COMPARE_RESULT
         )
       else ()
@@ -287,18 +287,18 @@ if (NOT TEST_SKIP_COMPARE)
     file (READ ${TEST_FOLDER}/${TEST_ERRREF} TEST_STREAM)
     list (LENGTH TEST_STREAM test_len)
     if (test_len GREATER 0)
-      if (WIN32)
-        configure_file(${TEST_FOLDER}/${TEST_ERRREF} ${TEST_FOLDER}/${TEST_ERRREF}.tmp NEWLINE_STYLE CRLF)
-        if (EXISTS "${TEST_FOLDER}/${TEST_ERRREF}.tmp")
-          file(RENAME ${TEST_FOLDER}/${TEST_ERRREF}.tmp ${TEST_FOLDER}/${TEST_ERRREF})
-        endif ()
-        #file (READ ${TEST_FOLDER}/${TEST_ERRREF} TEST_STREAM)
-        #file (WRITE ${TEST_FOLDER}/${TEST_ERRREF} "${TEST_STREAM}")
-      endif ()
+    #  if (WIN32) # no longer needed for CMake > 3.15
+    #    configure_file(${TEST_FOLDER}/${TEST_ERRREF} ${TEST_FOLDER}/${TEST_ERRREF}.tmp NEWLINE_STYLE CRLF)
+    #    if (EXISTS "${TEST_FOLDER}/${TEST_ERRREF}.tmp")
+    #      file(RENAME ${TEST_FOLDER}/${TEST_ERRREF}.tmp ${TEST_FOLDER}/${TEST_ERRREF})
+    #    endif ()
+    #    #file (READ ${TEST_FOLDER}/${TEST_ERRREF} TEST_STREAM)
+    #    #file (WRITE ${TEST_FOLDER}/${TEST_ERRREF} "${TEST_STREAM}")
+    #  endif ()
 
       # now compare the error output with the error reference
       execute_process (
-          COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_FOLDER}/${TEST_OUTPUT}.err ${TEST_FOLDER}/${TEST_ERRREF}
+          COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_FOLDER}/${TEST_OUTPUT}.err ${TEST_FOLDER}/${TEST_ERRREF}
           RESULT_VARIABLE TEST_ERRREF_RESULT
       )
       if (TEST_ERRREF_RESULT)
diff --git a/config/cmake/scripts/CTestScript.cmake b/config/cmake/scripts/CTestScript.cmake
index b142ade..f1dd662 100644
--- a/config/cmake/scripts/CTestScript.cmake
+++ b/config/cmake/scripts/CTestScript.cmake
@@ -9,7 +9,7 @@
 # If you do not have access to either file, you may request a copy from
 # help@hdfgroup.org.
 #
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.18)
 ########################################################
 # This dashboard is maintained by The HDF Group
 # For any comments please contact cdashhelp@hdfgroup.org
diff --git a/config/cmake/scripts/HDF5config.cmake b/config/cmake/scripts/HDF5config.cmake
index 3f46aed..ff13b84 100644
--- a/config/cmake/scripts/HDF5config.cmake
+++ b/config/cmake/scripts/HDF5config.cmake
@@ -15,7 +15,7 @@
 ### ctest -S HDF5config.cmake,BUILD_GENERATOR=VS201764 -C Release -VV -O hdf5.log         ###
 #############################################################################################
 
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.18)
 ############################################################################
 # Usage:
 #     ctest -S HDF5config.cmake,OPTION=VALUE -C Release -VV -O test.log
diff --git a/config/cmake/userblockTest.cmake b/config/cmake/userblockTest.cmake
index e6a278c..dde66c9 100644
--- a/config/cmake/userblockTest.cmake
+++ b/config/cmake/userblockTest.cmake
@@ -102,7 +102,7 @@ if (TEST_CHECKUB STREQUAL "YES")
 
   # now compare the outputs
   execute_process (
-      COMMAND ${CMAKE_COMMAND} -E compare_files ${CMAKE_IGNORE_EOL} ${TEST_HFILE}-ub.cmp ${TEST_HFILE}.cmp
+      COMMAND ${CMAKE_COMMAND} -E compare_files --ignore-eol ${TEST_HFILE}-ub.cmp ${TEST_HFILE}.cmp
       RESULT_VARIABLE TEST_RESULT
   )
 
diff --git a/config/cmake/wait_H5Tinit.cmake b/config/cmake/wait_H5Tinit.cmake
index b778765..a8781fe 100644
--- a/config/cmake/wait_H5Tinit.cmake
+++ b/config/cmake/wait_H5Tinit.cmake
@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.18)
 
 message(STATUS "Check for existence of ${HDF5_GENERATED_SOURCE_DIR}/H5Tinit.c")
 execute_process(COMMAND ls ${HDF5_GENERATED_SOURCE_DIR}/H5Tinit.c RESULT_VARIABLE H5TI_result OUTPUT_QUIET ERROR_QUIET)