gdb: How to get coredumps with FULL debug symbols?

[JackNickholson]

Hi the community!

This  question is exemplified around Evolution GNU email client, but the question is for any deb packaged <application>
OS: Linux Mint 22 Cinnamon

Example case: trying to start evolution via firejail; evolution crashes but unable to retrieve the GDB coredumps
              See the details: https://gitlab.gnome.org/GNOME/evolution/-/issues/2936

Pre-requisites done:

A) Without firejail, make evolution get started

1. Firejail installed (Ref-b)
2. If exists, rename the symlink 
    evolution -> /usr/bin/firejail *

B) ensure that GDB is enabled (Ref a & c & d)

3. cat /proc/sys/kernel/core_pattern  >> must show systemd-coredump
4. add the following line to ~/.bashrc
   export DEBUGINFOD_URLS="https://debuginfod.ubuntu.com"
5. Logout and log back in
6. echo $DEBUGINFOD_URLS must show https://debuginfod.ubuntu.com

C) Ensure the debug symbols are enabled in the system repos and installed via the them

7. In Software Sources in Mint, Enable 
   "Source Code Repo's" and "Debug Symbols"
8. In Synaptic Package Manager in Mint, browse the <application>'s (e.g. evolution's) binaries
   by searching the package/binary name:  
   
   e.g. "evolution" lists "evolution-dbgsym", "evolution-data-server-dbgsym", "evolution-data-server-dev" etc
9. Select the needed packages to be installed in 8 and press "Apply" in Synaptic Package Manager

D)

10. type gdb : e.g.

        gdb evolution
            Enable debuginfod for this session? (y or [n]) y
            If you are asked whether to continue without paging, enter c and press return. (You may need to do this multiple times.)
            Reading symbols from evolution...
            Reading symbols from /usr/lib/debug/.build-id/4d/4d009f97e0406663c73dafb95a9a4e83cda63a.debug...

11. Note that step 10, via debuginfod has also downloaded the 's debuginfo files to /home/$USER/.cache/debuginfod_client
    gdb is to show also the loaded dependencies debug symbols

Questions:

Q1) AFAIK, steps A-D ensures that WITHOUT firejail, one can get the good quality coredumps with FULL debug symbols. Any corrections?

If the answer to Q1 is yes, then the next step is to make GDB to work USING evolution started by firejail

Pre-requisites done:

E) To fix https://gitlab.gnome.org/GNOME/evolution/-/issues/2936#note_2303513, edit /etc/firejail/evolution.profile to make it look like:

include evolution.local
include globals.local

whitelist /var/mail
whitelist /var/spool/mail
whitelist ${HOME}/.config/dconf
whitelist ${HOME}/.bogofilter
whitelist ${HOME}/.cache/evolution
whitelist ${HOME}/.config/evolution
whitelist ${HOME}/.gnupg
whitelist ${HOME}/.local/share/evolution
whitelist ${HOME}/.pki
whitelist ${HOME}/.local/share/pki

include disable-common.inc
include disable-devel.inc
include disable-exec.inc
include disable-interpreters.inc
include disable-programs.inc

include whitelist-runuser-common.inc


ignore dbus-user none
ignore dbus-system none


whitelist /run/user/1000/at-spi/bus_0
whitelist /home/user/pki

caps.drop all
netfilter
nodvd
nogroups
noinput
nonewprivs
noroot
nosound
notv
nou2f
novideo
protocol unix,inet,inet6
seccomp

private-cache
private-dev
private-tmp
writable-var

restrict-namespaces

F) To help GDB to find the dbg symbols for the dependencies, copy

   /home/$USER/firejail/homes/evolution/.cache/debuginfod_client
   to
   /home/$USER/firejail/homes/evolution/.cache/debuginfod_client

G) firejail --private=$HOME/firejail/homes/evolution --profile=evolution.profile gdb --tui --args evolution %U

    Enable debuginfod for this session? (y or [n]) y
    Downloading seperate debug info for /usr/bin/evolution
    Warning: could not find '.gnu_debugaltlink' file for /usr/bin/evolution   <<<
    No debugging symbols found in evolution                                   <<<

H) At the time of G, firejail process is running for evolution with gdb with PID 45474

   firejail --list
        45474:user::firejail --private=/home/user/firejail/homes/evolution gdb --tui --args evolution %U 
            45475:user::firejail --private=/home/user/firejail/homes/evolution gdb --tui --args evolution %U 
                45483:user::gdb --tui --args evolution %U

QUESTIONS

Q2) Looking at G & H, gdb process runs under evolutions process, is this the problem?
Q3) Looking at G & H, Can an be GDB debugged under firejail? Which firejail process to debug? 45475, 45483 or 45474?
Q4) Looking at G, F didnt work. Is F needed to enable the debugging via GDB?
Q5) What other step(s) are needed to enable GDB coredumps via firejail?

REFs

a. https://handbook.gnome.org/issues/stack-traces.html
b. https://firejail.wordpress.com/2017/05/15/linux-mint-sandboxing-guide/#launchers
c. https://ubuntu.com/server/docs/about-debuginfod
d. https://ubuntu.com/server/docs/debug-symbol-packages

[JackNickholson]

while G is active

sudo gdb --pid 45475

didnt help either. Loads firejails debug symbols, not evolution's

[rusty-snake]

45475 is the pid of an firejail process

[JackNickholson]

Yes. Just checked with the processes: 45474, 45475; the same "No debugging symbols found in evolution" output when attached.
Wondering, is the command below incorrect to trigger evolution with gdb?

firejail --private=$HOME/firejail/homes/evolution --profile=evolution.profile \
  gdb --tui --args evolution %U

[kmk3]

Yes. Just checked with the processes: 45474, 45475; the same "No debugging
symbols found in evolution" output when attached. Wondering, is the command
below incorrect to trigger evolution with gdb?

firejail --private=$HOME/firejail/homes/evolution --profile=evolution.profile \
  gdb --tui --args evolution %U

Does it work with the following?

firejail --allow-debuggers --private='${HOME}/firejail/homes/evolution' --profile=evolution \
  gdb --tui --args /usr/bin/evolution %U