Hi again,
Then here is my current situation (after a LZ4 decompression, https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914934): root@hp-dark:/var/lib/systemd/coredump# file core.tracker-extract.1000.273d78802abc412f8e7a360fd7509e52.14743.1543436892000000 core.tracker-extract.1000.273d78802abc412f8e7a360fd7509e52.14743.1543436892000000: ELF 64-bit LSB core file, x86-64, version 1 (SYSV), SVR4-style, from '/usr/lib/tracker/tracker-extract', real uid: 1000, effective uid: 1000, real gid: 1000, effective gid: 1000, execfn: '/usr/lib/tracker/tracker-extract', platform: 'x86_64' root@hp-dark:/var/lib/systemd/coredump# gdb core.tracker-extract.1000.273d78802abc412f8e7a360fd7509e52.14743.1543436892000000 GNU gdb (Debian 8.2-1) 8.2 Copyright (C) 2018 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>;. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>;. For help, type "help". Type "apropos word" to search for commands related to "word"... "/var/lib/systemd/coredump/core.tracker-extract.1000.273d78802abc412f8e7a360fd7509e52.14743.1543436892000000": not in executable format: file format not recognized (gdb) quit I have installed: ii libde265-0-dbgsym:amd64 1.0.3-1+b1 amd64 debug symbols for libde265-0 ii libdvdcss2-dbgsym:amd64 1.4.2-1~local amd64 debug symbols for libdvdcss2 ii tracker-extract-dbgsym 2.1.5-3 amd64 debug symbols for tracker-extract because by another way (looking at /tmp/tracker-extract-files.XXXXX) I have found that the error is due to a Matroska video file. Finally I tried to look at https://wiki.debian.org/HowToGetABacktrace but it does not mention systemd-coredump at all, and then it is not clear when the need is for a user or session daemon/service debugging because in my case it is not explicitly launching a specific command to get the error. Regards, Patrice
