Fix FTBFS by appeasing compiler warnings
The first commit fixes building from source with GCC-14 by explicitly casting an absolute address literal to a pointer, avoiding [-Wint-conversion]
. (Closes: #1075615)
The second commit deals with some additional warnings which were not treated as errors including by handling a couple of error conditions previously ignored. This results in no compiler warnings on i386, although some remain with amd64 builds.
Feel free only to merge the first commit if you only want to deal with the FTBFS issue affecting trixie although I think getting rid of warnings can help with other tasks by removing noise.