message: checking errors
diff: @@ -146,11 +146,21 @@ foreach(i RANGE 0 ${len1})
  endif()
  execute_process(COMMAND tar xf ${mat}.tar.gz
  + RESULT_VARIABLE STATUS
  WORKING_DIRECTORY ${CMAKE_MATRICES_DIR})
  + if(STATUS AND NOT STATUS EQUAL 0)
  + message(FATAL_ERROR "uncompressing failed, aborting.")
  + endif()
  file(RENAME ${CMAKE_MATRICES_DIR}/${mat}/${mat}.mtx ${CMAKE_MATRICES_DIR}/${mat}.mtx)
  execute_process(COMMAND ${PROJECT_BINARY_DIR}/mtx2csr.exe ${mat}.mtx ${mat}.csr
  + RESULT_VARIABLE STATUS
  WORKING_DIRECTORY ${CMAKE_MATRICES_DIR})
  + if(STATUS AND NOT STATUS EQUAL 0)
  + message(FATAL_ERROR "mxt2csr.exe failed, aborting.")
  + else()
  + message(STATUS "${mat} success.")
  + endif()
  # TODO: add 'COMMAND_ERROR_IS_FATAL ANY' once cmake supported version is 3.19
  file(REMOVE_RECURSE ${CMAKE_MATRICES_DIR}/${mat}.tar.gz ${CMAKE_MATRICES_DIR}/${mat} ${CMAKE_MATRICES_DIR}/${mat}.mtx)
  