this test is skipped because it's really long and heavy, could be >1500s
do not build/install it either
see https://bugs.gentoo.org/977020
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -233,22 +233,6 @@ if(WITH_INCHI)
   endforeach(test ${inchitests})
 endif(WITH_INCHI)
 
-# ###########################################################
-# roundtrip
-# ###########################################################
-add_executable(roundtrip roundtrip.cpp)
-target_link_libraries(roundtrip ${libs})
-
-if(NOT BUILD_SHARED AND NOT BUILD_MIXED)
-  set_target_properties(roundtrip PROPERTIES LINK_SEARCH_END_STATIC TRUE)
-endif()
-
-install(TARGETS roundtrip
-  RUNTIME DESTINATION bin
-  LIBRARY DESTINATION lib${LIB_SUFFIX}
-  ARCHIVE DESTINATION lib${LIB_SUFFIX}
-)
-
 # ##########################
 # Tests wrapped in Python #
 # ##########################