add find_hdf5 option (default true)

CMakeLists.txt

@@ -43,23 +43,43 @@ if(hdf5_parallel)
   include(cmake/check_mpi.cmake)
   check_mpi_version()
 
-  find_package(HDF5 COMPONENTS Fortran parallel)
+  if(find_hdf5)
+    find_package(HDF5 COMPONENTS Fortran parallel)
+  endif()
 
   if(HDF5_FOUND)
+    if(HDF5_VERSION VERSION_LESS 1.10.2)
+      message(WARNING "HDF5 >= 1.10.2 is needed for HDF5-MPI")
+    endif()
     include(cmake/hdf5_compression.cmake)
     hdf5_compression_flag()
   else()
+    # HDF5 install fails to work (link) if prior HDF5 library is installed there
+    find_package(HDF5 CONFIG PATHS ${CMAKE_INSTALL_PREFIX} NO_DEFAULT_PATH QUIET)
+    if(HDF5_FOUND)
+      message(FATAL_ERROR "HDF5 library already installed: ${HDF5_DIR}
+      Please pick a new install location or completely remove the old HDF5 install directory.
+      Otherwise, HDF5 will fail to link correctly with prior version and this version mixed.")
+    endif()
     include(cmake/hdf5.cmake)
   endif()
 else()
-  find_package(HDF5 COMPONENTS Fortran)
+  if(find_hdf5)
+    find_package(HDF5 COMPONENTS Fortran)
+  endif()
+  if(NOT HDF5_FOUND)
+    # HDF5 install fails to work (link) if prior HDF5 library is installed there
+    find_package(HDF5 CONFIG PATHS ${CMAKE_INSTALL_PREFIX} NO_DEFAULT_PATH QUIET)
+    if(HDF5_FOUND)
+      message(FATAL_ERROR "HDF5 library already installed: ${HDF5_DIR}
+      Please pick a new install location or completely remove the old HDF5 install directory.
+      Otherwise, HDF5 will fail to link correctly with prior version and this version mixed.")
+    endif()
+    include(cmake/hdf5.cmake)
+  endif()
   set(hdf5_parallel_compression ".false.")
 endif()
 
-if(HDF5_VERSION VERSION_LESS 1.10.2)
-  message(WARNING "HDF5 >= 1.10.2 is needed for HDF5-MPI")
-endif()
-
 # --- h5fortran library
 
 configure_file(src/hdf5_config.f90.in hdf5_config.f90 @ONLY)

options.cmake

@@ -1,7 +1,7 @@
-include(GNUInstallDirs)
-
 message(STATUS "${PROJECT_NAME} ${PROJECT_VERSION}  CMake ${CMAKE_VERSION}")
 
+option(find_hdf5 "search for HDF5 and Zlib" true)
+
 option(benchmark "Run benchmarks")
 option(coverage "Code coverage tests")
 option(tidy "Run clang-tidy on the code")
@@ -16,6 +16,7 @@ if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT AND ${PROJECT_NAME}_IS_TOP_LEVEL)
   set(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}/local" CACHE PATH "install prefix" FORCE)
 endif()
 
+set_property(DIRECTORY PROPERTY EP_UPDATE_DISCONNECTED true)
 
 if(BUILD_SHARED_LIBS AND MSVC)
   message(WARNING "Intel oneAPI has trouble with shared libs in general on Windows, try

scripts/CMakeLists.txt

@@ -6,7 +6,6 @@ LANGUAGES C Fortran
 )
 
 option(hdf5_parallel "build HDF5 parallel MPI" on)
-option(zlib_legacy "use legacy zlib 1.x")
 
 # --- system checks
 file(MAKE_DIRECTORY ${CMAKE_INSTALL_PREFIX})