Move ShowHelp test into Testing.cmake

cmake/CMakeLists.txt

@@ -522,9 +522,6 @@ if(BUILD_EXE)
   set_target_properties(lmp PROPERTIES OUTPUT_NAME ${LAMMPS_BINARY})
   install(TARGETS lmp DESTINATION ${CMAKE_INSTALL_BINDIR})
   install(FILES ${LAMMPS_DOC_DIR}/lammps.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1 RENAME ${LAMMPS_BINARY}.1)
-  if(ENABLE_TESTING)
-    add_test(ShowHelp ${LAMMPS_BINARY} -help)
-  endif()
 
   enable_language(C)
   get_filename_component(MSI2LMP_SOURCE_DIR ${LAMMPS_TOOLS_DIR}/msi2lmp/src ABSOLUTE)

cmake/Modules/Testing.cmake

@@ -28,6 +28,8 @@ if(ENABLE_TESTING AND BUILD_EXE)
                     "https://github.com/lammps/lammps-testing in LAMMPS_TESTING_SOURCE_DIR")
   endif()
 
+  add_test(ShowHelp ${CMAKE_BINARY_DIR}/${LAMMPS_BINARY} -help)
+
   if(EXISTS ${LAMMPS_TESTING_SOURCE_DIR})
     message(STATUS "Running test discovery...")