Comment 13 for bug 1918035

verified:

root@focal-vm:~# dpkg -l libc6-dbg | grep ^ii
ii libc6-dbg:amd64 2.31-0ubuntu9.7 amd64 GNU C Library: detached debugging symbols
root@focal-vm:~# gdb -q /bin/date
Reading symbols from /bin/date...
(No debugging symbols found in /bin/date)
(gdb) starti
Starting program: /usr/bin/date

Program stopped.
0x00007ffff7fd0100 in ?? () from /lib64/ld-linux-x86-64.so.2
(gdb) br _dl_debug_state
Breakpoint 1 at 0x7ffff7fe11d0
(gdb) r
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /usr/bin/date

Breakpoint 1, 0x00007ffff7fe11d0 in _dl_debug_state () from /lib64/ld-linux-x86-64.so.2
(gdb) bt
#0 0x00007ffff7fe11d0 in _dl_debug_state () from /lib64/ld-linux-x86-64.so.2
#1 0x00007ffff7fd2fd1 in ?? () from /lib64/ld-linux-x86-64.so.2
#2 0x00007ffff7febc3b in ?? () from /lib64/ld-linux-x86-64.so.2
#3 0x00007ffff7fd104c in ?? () from /lib64/ld-linux-x86-64.so.2
#4 0x00007ffff7fd0108 in ?? () from /lib64/ld-linux-x86-64.so.2
#5 0x0000000000000001 in ?? ()
#6 0x00007fffffffe8e9 in ?? ()
#7 0x0000000000000000 in ?? ()
(gdb) quit
A debugging session is active.

 Inferior 1 [process 13368] will be killed.

Quit anyway? (y or n) y
root@focal-vm:~# apt install --allow-downgrades -t focal-proposed libc6-dbg
[...]
Unpacking libc6-dbg:amd64 (2.31-0ubuntu9.9) over (2.31-0ubuntu9.7) ...
[...]

root@focal-vm:~# gdb -q /bin/date
Reading symbols from /bin/date...
(No debugging symbols found in /bin/date)
(gdb) starti
Starting program: /usr/bin/date

Program stopped.
0x00007ffff7fd0100 in _start () from /lib64/ld-linux-x86-64.so.2
(gdb) br _dl_debug_state
Breakpoint 1 at 0x7ffff7fe11e0: file dl-debug.c, line 73.
(gdb) r
The program being debugged has been started already.
Start it from the beginning? (y or n) n
Program not restarted.
(gdb) c
Continuing.

Breakpoint 1, __GI__dl_debug_state () at dl-debug.c:73
73 dl-debug.c: No such file or directory.
(gdb) bt
#0 __GI__dl_debug_state () at dl-debug.c:73
#1 0x00007ffff7fd2fd1 in dl_main (phdr=<optimized out>, phnum=<optimized out>, user_entry=<optimized out>, auxv=<optimized out>) at rtld.c:1661
#2 0x00007ffff7febc4b in _dl_sysdep_start (start_argptr=start_argptr@entry=0x7fffffffe6f0, dl_main=dl_main@entry=0x7ffff7fd15e0 <dl_main>) at ../elf/dl-sysdep.c:252
#3 0x00007ffff7fd104c in _dl_start_final (arg=0x7fffffffe6f0) at rtld.c:449
#4 _dl_start (arg=0x7fffffffe6f0) at rtld.c:539
#5 0x00007ffff7fd0108 in _start () from /lib64/ld-linux-x86-64.so.2
#6 0x0000000000000001 in ?? ()
#7 0x00007fffffffe8e9 in ?? ()
#8 0x0000000000000000 in ?? ()
(gdb) Quit