A simple case. (OS: FC3_x64, compiler is native (gcc 3.4.2)). I make a f77 program, say, tmp.F: program tmp print *, Hello end Then, I compile it: g77 -c -g tmp.F and open the object file tmp.o in gdb or ddd. In gdb source can't be seen ("list tmp.F:1" -> "No source file tmp.F"), but in ddd I do see source, but in addition to tmp.F there is one more file /tmp/ccwmF4Ox.f, that ddd tries to open but can't (it doesn't exist actually). Could anyone explain or comment the situation. Is this a problem of gdb or gcc? Thanks in advance. Konstantin.