Hi, currently (on Fedora Core 6) after installation of /usr/lib/debug separate debuginfo files the backtraces no longer display some libc functions: #5 #6 0x00c98402 in __kernel_vsyscall () #7 0x0077ebc6 in ?? () from /lib/i686/nosegneg/libc.so.6 #8 0x08048444 in main () at doublesym.c:15 while after `rm -rf /usr/lib/debug': #5 #6 0x0087b402 in __kernel_vsyscall () #7 0x0077ebc6 in __pause_nocancel () from /lib/i686/nosegneg/libc.so.6 #8 0x08048444 in main () at doublesym.c:15 It is (I believe) due to the fact the system libc gets prelinked to some address but the separate debuginfo file is not updated for the prelinked address. `matching_bfd_sections' will fail to match afterwards. Not sure if the testcase properly fails on all systems, it works for me with the prelinking in effect. Regards, Jan