12:45:22puchaczhi - you may want to know that it is not possible to compile serapeum; I tried (ql:quickload :cl-data-structures) that use serapeum and got this:
12:45:25puchacz; BIR verification failed. The IR is in an inconsistent state.
12:45:25puchacz; This probably indicates a problem in the compiler; please report it.
12:46:26puchaczmy quicklisp uses ultralisp distribution
12:47:21puchaczbut both serapeum and cl-data-structures are not very popular, so this issue may not be very important. I managed to live without them for years.