/usr/include/ql/pricingengines/barrier/ is in libquantlib0-dev 1.12-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ql/pricingengines/barrier/all.hpp
/usr/include/ql/pricingengines/barrier/analyticbarrierengine.hpp
/usr/include/ql/pricingengines/barrier/analyticbinarybarrierengine.hpp
/usr/include/ql/pricingengines/barrier/binomialbarrierengine.hpp
/usr/include/ql/pricingengines/barrier/discretizedbarrieroption.hpp
/usr/include/ql/pricingengines/barrier/fdblackscholesbarrierengine.hpp
/usr/include/ql/pricingengines/barrier/fdblackscholesrebateengine.hpp
/usr/include/ql/pricingengines/barrier/fdhestonbarrierengine.hpp
/usr/include/ql/pricingengines/barrier/fdhestonrebateengine.hpp
/usr/include/ql/pricingengines/barrier/mcbarrierengine.hpp