make lammps-shell test compatible with MULTI-CONFIG CMake builders

unittest/tools/CMakeLists.txt

@@ -8,12 +8,18 @@ if(CMAKE_VERSION VERSION_LESS 3.12)
 else()
   find_package(Python 3.5 COMPONENTS Interpreter)
 endif()
+get_property(BUILD_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
+if(BUILD_IS_MULTI_CONFIG)
+  set(LAMMPS_SHELL_EXE_DIR ${CMAKE_BINARY_DIR}/$<CONFIG>)
+else()
+  set(LAMMPS_SHELL_EXE_DIR ${CMAKE_BINARY_DIR})
+endif()
 
 if(Python_EXECUTABLE)
   if(BUILD_LAMMPS_SHELL)
     add_test(NAME LammpsShell
       COMMAND ${Python_EXECUTABLE} -u ${CMAKE_CURRENT_SOURCE_DIR}/test_lammps_shell.py -v
-      WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+      WORKING_DIRECTORY ${LAMMPS_SHELL_EXE_DIR})
   endif()
 else()
   message(STATUS "Skipping Tests for LAMMPS tools: no suitable Python interpreter")