I try to watch how programs work by running them by the 'Qt Creator' debugger. For better orientation I'd like to see also the system (core) utilities fully in the call stack window as I am used from the MS Visual Studio 6.0, not only to see their assembly code. For the utilities, the 'Qt Creator' debugger displays only that their debug symbols are not available. (Sometimes, the system generates bug reports for its developers; the bug report dialog has requested installing such symbols only for a particular program.) How can I get the core debug symbols? (Without translating the whole Ubuntu version. I use the 'Update Manager' to install updates regularly. My

directory contains only one empty file. I have not found it in the 'Ubuntu software center' nor do I see if some of the packages at the http://packages.ubuntu.com/precise/x11/ is what I seek.) Thanks!

  • 2
    See this page. Jun 23, 2014 at 16:42
  • @saiarcot895 It works, please formulate your comment as an answer so that I can set it as an accepted one. Where are the debug symbols placed in my filesystem? Thanks! Jun 24, 2014 at 8:57

4 Answers 4


Packages in Ubuntu have their debugging symbols stored in a separate repo. To download these debugging symbols, run (copy and paste):

printf "deb http://ddebs.ubuntu.com %s main restricted universe multiverse\n" $(lsb_release -cs){,-updates,-security,-proposed} | \
 sudo tee -a /etc/apt/sources.list.d/ddebs.list

to add the repo links into /etc/apt/sources.list.d/ddebs.list (This makes it easier to remove the repo). Alternatively, you can also copy each of the deb links into Software Sources and add them from there (Note that you'll likely need to replace $(lsb_release -cs) with the Ubuntu release that you're running).

To download the debugging symbols for package, you can just install package-dbgsym or, in some cases, package-dbg. Note that packages from a PPA don't have debugging symbols available from repos, and that it's the maintainer's responsibility to provide a package that contains the debugging symbols, usually in a package named package-dbg.

Debugging symbols are installed in /usr/lib/debug, although gdb automatically reads in debugging symbols if available and that you don't manually need to specify a location to look in. Depending on the Debhelper Compatibility version of the package, debugging symbols may either be located in a folder with the name of the build ID located inside .build-id (>= 9), or may be located relative to where the executable would be installed (< 9). For example, if you were looking for the location of the debugging symbols for /usr/bin/zip, and the version is less than 9, it would be in /usr/lib/debug/usr/bin/zip.

To remove all debugging symbols and the repo, run sudo apt-get remove \.*-dbgsym to remove all -dbgsym packages, and sudo rm /etc/apt/sources.list.d/ddebs.list to remove the debugging symbols repo.

  • 5
    Just a note that PPAs now do generate dbgsym packages. But you need to add a deb line with "main/debug", like: "deb ppa.launchpad.net/USER/PPA/ubuntu vivid main/debug" Mar 18, 2016 at 13:32
  • 1
    As of bionic, the ddebs repo doesn't have a Release file for bionic-security Jul 2, 2018 at 13:44
  • I got "E: The repository 'ddebs.ubuntu.com impish-security Release' does not have a Release file." after sudo apt update and couldn't see any dbg packages, possibly same that Paulo was referring to. Jan 4, 2022 at 13:39

Adding to Evans answer: On Ubuntu 18.04 and later you use the command

sudo apt install ubuntu-dbgsym-keyring

to install the GPG keys. (According to https://wiki.ubuntu.com/Debug%20Symbol%20Packages )


Adding to saircot859's answer. You also have to install the GPG key for the repositories as described here: https://wiki.ubuntu.com/Debug%20Symbol%20Packages

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 428D7C01 C8CAB6595FDFF622
  • Linked wiki page was updated. On Ubuntu 18.04 LTS and newer, use sudo apt install ubuntu-dbgsym-keyring.
    – user7610
    May 9, 2020 at 19:30

Also get the correct source code with apt source

In addition to the symbols, you will also to get the source with apt source as mentioned at:

and then point GDB to them with substitute-path as mentioned at: https://stackoverflow.com/questions/23868252/gdb-source-path

Some fully working commands on Ubuntu 22.04, e.g. to debug ls from coreutils:

# Get debug symbols.
printf "deb http://ddebs.ubuntu.com %s main restricted universe multiverse\n" $(lsb_release -cs){,-updates,-security,-proposed} | \
 sudo tee -a /etc/apt/sources.list.d/ddebs.list
sudo apt install ubuntu-dbgsym-keyring
sudo apt update
sudo apt install coreutils-dbgsym

# Get source as per: https://askubuntu.com/questions/496549/error-you-must-put-some-source-uris-in-your-sources-list
# Produces directory "coreutils-8.32"
sudo cp /etc/apt/sources.list /etc/apt/sources.list~
sudo sed -Ei 's/^# deb-src /deb-src /'
/etc/apt/sources.list sudo apt-get update
apt source coreutils

# Run ls pointing to the downloaded source.
gdb -ex 'set substitute-path . coreutils-8.32' ls

in which I see the source correctly as:

(gdb) start
Temporary breakpoint 1 at 0x4d20: file src/ls.c, line 1622.
Starting program: /usr/bin/ls 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Temporary breakpoint 1, main (argc=1, argv=0x7fffffffce08) at src/ls.c:1622
warning: Source file is more recent than executable.
1622    {
(gdb) l
1617      signal_setup (false);
1618    }
1620    int
1621    main (int argc, char **argv)
1622    {
1623      int i;
1624      struct pending *thispend;
1625      int n_files;

The choice of set substitute-path . is because without substitute-path it would fail with:

1622    src/ls.c: No such file or directory.

so we help GDB find the source by making it convert . to coreutils-8.32/ where the src/ lives.

GDB step debug into glibc

The exact same procedure works for shared libraries. E.g. to GDB step debug glibc as asked at:

In that case, the debug symbols already appear to come preinstalled, otherwise we would need:

sudo apt install libc6-dbg

and then get source with:

apt source libc6

which produces directory: glibc-2.35.

We then make a C hello world to test with:


#include <stdio.h>

int main(void) {

If we try to compile, GDB and go into glibc

gcc -ggdb3 -O0 -std=c99 -Wall -Wextra -pedantic -o main.out main.c
gdb main.out


(gdb) start
Temporary breakpoint 1 at 0x1151: file main.c, line 4.
Starting program: /home/ciro/tmp/main.out 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Temporary breakpoint 1, main () at main.c:4
4           puts("hello");
(gdb) s
__GI__IO_puts (str=0x555555556004 "hello") at ./libio/ioputs.c:33
33      ./libio/ioputs.c: No such file or directory.

we see that the library also searches for files under ./, so once again we:

set substitute-path . glibc-2.35

and now we can see the source:

(gdb) l
28      #include <string.h>
29      #include <limits.h>
31      int
32      _IO_puts (const char *str)
33      {
34        int result = EOF;
35        size_t len = strlen (str);
36        _IO_acquire_lock (stdout);

Some other versions of Ubuntu had sources at an absolute location like:


in which case you would instead want:

set substitute-path /tmp/build138741687/ glibc-2.35

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .