fixed problem with input-sandbox.tgz not being updated

Fixes LBCORE-1036.

See merge request !17

LbUtils/cmake/GangaTools.cmake

@@ -53,15 +53,12 @@ function(ganga_input_sandbox)
                     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
                     DEPENDS ganga-clean-install)
 
-  add_custom_command(OUTPUT ${GANGA_INPUT_SANDBOX_FILE}
-                     COMMAND ${CMAKE_COMMAND} -E remove -f ${GANGA_INPUT_SANDBOX_FILE}
-                     COMMAND ${CMAKE_COMMAND} -E tar cfz ${GANGA_INPUT_SANDBOX_FILE}
-                             run ${CMAKE_PROJECT_NAME}_${CMAKE_PROJECT_VERSION}
-                     WORKING_DIRECTORY ${GANGA_BINARY_DIR}
-                     DEPENDS ganga-dist-prepare)
-
   add_custom_target(ganga-input-sandbox
-                    DEPENDS ${GANGA_INPUT_SANDBOX_FILE}
+                    COMMAND ${CMAKE_COMMAND} -E remove -f ${GANGA_INPUT_SANDBOX_FILE}
+                    COMMAND ${CMAKE_COMMAND} -E tar cfz ${GANGA_INPUT_SANDBOX_FILE}
+                            run ${CMAKE_PROJECT_NAME}_${CMAKE_PROJECT_VERSION}
+                    WORKING_DIRECTORY ${GANGA_BINARY_DIR}
+                    DEPENDS ganga-dist-prepare
                     COMMENT "Preparing input sandbox tarball")
 endfunction()