LIBSOLV is a library that is tightly bound with LIBDNF and DNF. After the last release, there are many changes in code that are built on top of each other or require changes in related components, but not all relationships could be easily identified. With backporting only particular features, DNF team cannot ensure 100% functionality and there is a high risk of problems in the stability or in incomplete functionality. It is required by Bug 2174869 - [RFE] requesting the -W flag for testsolv which can be seen in upstream testsolv