unittests: fix pythonpath

Author: ahoarau

unittest/cpp/CMakeLists.txt

@@ -23,9 +23,12 @@ function(eigenpy_add_test name)
     NAME ${test_name}
     COMMAND $<TARGET_FILE:Python::Interpreter> ${CMAKE_CURRENT_SOURCE_DIR}/test_${name}.py
   )
-  set_tests_properties(
-    ${test_name}
-    PROPERTIES ENVIRONMENT "PYTHONPATH=$<TARGET_FILE_DIR:${name}>" DEPENDS ${name}
+  set_property(
+    TEST ${test_name}
+    PROPERTY
+      ENVIRONMENT_MODIFICATION
+        "PYTHONPATH=path_list_prepend:$<TARGET_FILE_DIR:eigenpy>/.."
+        "PYTHONPATH=path_list_prepend:$<TARGET_FILE_DIR:${name}>/.."
   )
 endfunction()