Immer mit dem Fehler
"[dcc32 Fatal Error] System.Variants.pas(1271): E2158 System.Variants
unit out of date or corrupted: missing '@VarCast'"
VarCast is declared as _VarCast, so in theory to make it work you need to strip all the functions in System.Variants.pas from these and adjust the whole
unit to call them stripped code, though there might be something hidden to surprise you, which need to adjust system.pas itself, that most likely impossible with Delphi compiler.
If rebuilding the whole
RTL (after making changes) is possible then that is the right way, in my opinion.
In case you succeeded in rebuilding the
RTL, then i suggest to add global hooks with minimum interaction with the current code and declarations, these hooks and callback can be used for logging, and the
RTL might still be compatible with default
RTL, just food for thought.