Questions tagged [debugging]
is a process of finding and reducing the number of bugs, or defects, in a computer program, thus making it behave as expected
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(How) can I set source path (in debuginfo) when building debian package
I need debuginfo for some libraries, for example gstreamer (which are not available in debian repo), but can be built using source packages. However it turns out that the source paths in the debug ...
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Get a log of everything GParted does when re-sizing a btrfs filesystem
When I use GParted to do some complicated partition and file system manipulation it gives the option to see the details of what steps it took. But this does not give all the details of what underlying ...
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Bottom row of keys will not type, unless they are held down for a random(?) amount of seconds, to which they then work for a bit before regressing
System
$ uname -r
6.6.23-1-rt28-MANJARO
$ cat /etc/*release
Manjaro Linux
DISTRIB_ID="ManjaroLinux"
DISTRIB_RELEASE="24.0.0"
DISTRIB_CODENAME="Wynsdey"
...
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How to check consistency of a generated web site using recursive HTML parsing
I have a FOSS project whose web site is generated by asciidoc and some custom scripts as an horde (thousands) of static files locally in the source files' repo, copied into another workspace and ...
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Does an echo to network command exist in debian?
Does some sort of command like:
echotonet "this"
or
cat file.txt > echonet
that could allow one to easily paste text document data to a service like paste.debian.net ?
I often use ...
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objdump `--adjust-vma` destroys debug info
When using the --adjust-vma option of objdump all the functions get squashed together, as if there is no debug information about where each function starts.
I'll demonstrate with the following simple ...
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GDB 'section' command doesn't seem to work as expected
As I understand it, the section command can be used to tell gdb that a specific section of the object file is loaded in a specific address. In my understanding this should also entail relocating all ...
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How to start a minimal Wayland session from command line?
A way to debug X is that I start an X server (X -ac :0), then an xterm (DISPLAY=:0 xterm) and a WM on it (DISPLAY=:0 icewm).
It is unthinkably useful is there is a display problem.
What can I do with ...
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Plugging in an external DVD drive causes ls, sudo, new SSH connections refused.... what happened?
Title says it all. But I plugged in an external DVD drive into my Raspberry Pi running Raspbian. It says its Linux compatible
However when I actually plug it into the device. Everything goes wrong in ...
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How to not display the LibreOffice file picker / loader when closing any LibreOffice application?
Until today, when I closed any LibreOffice application (e.g. Writer, Calc, Draw, Impress, etc.) in Linux Mint, the expected happened: LibreOffice would close.
Now, suddenly, when I close any ...
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can't get permissions for debug folder with a custom program
I am running a program on kali Linux. The program uses Openssl and some other networking libraries. When I try to run the program I get the output below:
Failed to open /sys/kernel/debug/ieee80211/...
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AWStats stuck, but no output on strace: How to debug?
A Perl script is stuck,
root 1317478 99.8 0.0 264072 22516 ? R 04:57 478:37 /usr/bin/perl /usr/share/awstats/wwwroot/cgi-bin/awstats.pl -config=domain.tld-http -staticlinks -configdir=/...
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How to debug WINE?
I've been using WINE for years for a program called CLUEWIN. This is a pretty simple win32 application (a dictionary). It has no noteworthy features and has always worked, for around 20 years. The ...
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How to debug a binary file with gdb
I currently have a binary program that usually ends locking up after some time using. I can cause it when clicking on the bar on the right side of the screen and moving it swiftly with mouse's left ...
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How to enable debug messages for pam_systemd_home.so?
The manual for pam_systemd_home states that debug messages can be enabled with debug=yes, but they don't state where to put it.
I tried adding the options to the relevant lines in pam.d/system-auth, ...
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XDP generic transmit packets to loopback interface dropped
I'm trying to transmit udp packets via xdp (receives work just fine) but the packets are dropped before udp processing.
Kernel: Linux fedora 6.5.12-300.fc39.x86_64 #1 SMP PREEMPT_DYNAMIC Mon Nov 20 22:...
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How to debug bzImage's decompress?
I already know that vmlinux is needed when debugging the kernel through gdb.
But I need to debug the decompress and EFI entrypoint of bzImage.
In this case, how can I debug bzImage with gdb?
Currently,...
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How do I find out reason of missing packets in response to `sendto` syscall?
strace ... -e sendto shows a successful (i.e. positive return value) outcome of trying to send a UDP datagram somewhere, but tcpdump -i any in that network namespace does not show anything relevant in ...
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Is there a way to show the kernel panic error message on the screen?
I'm currently running EndeavourOS, and I was wondering if there was possibly a way in to, in an event of a kernel panic, show the kernel panic message on screen/in the gui, similarly to a BSOD or mac ...
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Debugging memory leakage: No backtrace saved in core dump after segmentation fault
I am working on an embedded Linux system (kernel-5.10.186), and I want to debug a memory leakage in a program.
With pmap -x PID, I found the process's heap is increasing consistently.
To figure out ...
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Latency on pselect caused by other user space processes
I have the following pre-condition on Linux:
I'm using a process to read serial data using pselect on a serial device /dev/ttySX.
Data comes in at a stable frequency of 400 Hz.
To optimize latency of ...
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How do I debug code from dylib in lldb
I have a sketch of code in rust that uses dynamically linked ffmpeg library.
How do I actually see the code of ffmpeg inside lldb.
I've modified portfile of ffmpeg6 by adding this lines.
configure....
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How to debug an SSH-tunnel that doesn't work (SSH in itself works)?
I posted a question at Ask Different about SSH tunneling of VNC and SMB on MacOS because I thought it was specific for Mac, but it doesn't seem so. In short, I can SSH from my machine A to machine B (...
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What's the successor of libgcc1-dbg in Debian 11 and onward
I previously had libgcc1-dbg (and other debug symbol packages) installed on Debian 10 "buster" to get readable stack traces in failure cases or to inspect core files.
It seems, that package ...
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How to report a randomly occurring system freeze?
I'm running debian sid (unstable), and have had a few situations where the system freezes, becoming unresponsive and forcing me to reboot the system. This has happened during work video calls (but not ...
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tmux continues using variables that are no longer defined in .bashrc
I am trying to reset my .bashrc, because it has become bloated and it takes long to start a console.
For this I did the following:
cp /etc/skel/.bashrc ~/.bashrc
This worked for the normal login bash ...
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quick-swap TUI mode while using vi keybindings in GDB
In the default mode of gdb, pressing ctrl+x a turns on and off the UI, and ctrl+x 2 cycles through different split views. There are a number of similar useful shortcuts.
I can turn on vi emulation ...
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How to clear the /sys/kernel/debug/tracing/trace_pipe quickly?
I am using the bpf_printk() helper to print to the kernel debug to trace some BPF programs. The usage is as follows:
#include <stdio.h>
#include <linux/bpf.h>
#include <sys/socket.h>...
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Is is possible to configure cppcheck as your linter for nano?
Good debugging tools can save you a lot of time when you are writing code. In nano, it's nice that with bash scripts, you can just hit alt+b to find syntax errors before you try running it.
However, I ...
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Permission denied for user in group (group has directory write permissions)
I'm getting Permission Denied when attempting to create/touch files in a directory with group ownership permissions.
touch /data/www/acoder.txt
[acoder@box]$ touch /data/www/acoder.txt
touch: cannot ...
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GDB fails to download debuginfo for math.h
I have a simple clock program that uses math.h functions. I am currently on Kubuntu 21.10, the GCC version is (Ubuntu 12.2.0-3ubuntu1) 12.2.0, and the GDB version is (Ubuntu 12.1-3ubuntu2) 12.1.
The ...
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1
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How to read and debug SSH verbose-mode?
Let's say I use this command:
ssh -vvv user@server
I get an output similar to this:
send packet: type 21
ssh_set_newkeys: mode 1
receive packet: type 6
SSH2_MSG_SERVICE_ACCEPT received
receive packet:...
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How to diagnose a sharp, sudden increase in the frequency with which processes enter the D ("uninterruptible sleep") state
The Linux cluster I work on recently started getting frozen for a few minutes at a time. I've determined that the reason for this behavior is that processes are very frequently landing in the D (&...
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Redirect output of current script to a socket
I am trying to debug a shell script executing on a remote server, where I do not have access to the standard output of the script. Can I redirect the output to go over a socket?
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Systemtap probe kernel module function while that module is loaded
How to use a Systemtap probe on a kernel module function while that module is loaded. I am trying to print the functions being called for a particular module while it is being loaded. Suppose I have a ...
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Debug segfault race condition
I can provoke a race condition that gives output similar to this in dmesg:
[ 5432.541379] perl[408327]: segfault at 22 ip 0000564eb8af9cc2 sp 00007ffec318cea0 error 6 in perl[564eb8af7000+1a1000]
[ ...
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sh script won't run, (unexpected end of file) but the individual lines execute fine
Below is what I'm attempting to run on my remote machine, and I'm getting 'Unexpected end of file'.
However, if i take the lines and paste them into the CLI, it executes normally.
# if [ -f running....
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3
answers
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Temporarily unset bash option -x
I like to use set -x in scripts to show what's going on, especially if the script is going to run in a CI/CD pipeline and I might need to debug some failure post-hoc.
One annoyance with doing this is ...
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Bash truncates long PS4 strings
I am trying to debug a large build project which calls a bunch of bash scripts. Someone suggested modifying PS4 so I set it to the following snippet in order to print the path of the script and the ...
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C++ How to debug a WM/DE or X.org crash?
I have a huge code that deals with sockets, threads and processes and it is a complete mess... While editing recently, my WM crashed after I executed my code. Since every window is killed, I can't ...
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ansible echo to terminal when condition is found
How can I have the output printed to the terminal when condition is met using lineinfile
- lineinfile:
path: /home/pc/date.txt
state: present
line: 'yes'
regexp: '^\s*Wednesday\s*$'
...
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3k
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Permission error when attaching GDB to PID of running process
I have such a toy C++ program
#include <iostream>
int main() {
int n{};
std::cin >> n; // waits for input
std::cout << n << std::endl;
}
which pauses upon ...
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Why is my script misbehaving sometimes? [duplicate]
I have created a script that can split an audio file into smaller files via ffmpeg using timestamps, and another script which can take in timestamps & names in batches. My use for this script ...
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3
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Tool to detect errors in application's execution logic
I want to detect errors in application's execution logic. E.g.:
forgot to call free() on address returned by malloc()
did not close file handle returned by open()
invalid flags passed to open()
...
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CodeLLDB for VSCode not working with remote gdbserver
I'm currently trying to set up remote debugging on a Raspberry Pi using the CodeLLDB plugin for Visual Studio Code and gdbserver. Unfortunately this doesn't seem to work, since every breakpoint I set ...
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409
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Testing an application under Eclipse with sudo elevation
I am developing a C++ application that requires root privilege. I am working under Eclipse and I would like to be able to launch/debug from it.
I know I could start Eclipse as a root, but I am looking ...
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165
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What is the complete list of file functions equivalent to the "strace -e file" options?
According to man strace the -e file option traces all syscalls which take a file name as an argument. What is the whole set?
%file
file Trace all system calls which take a file ...
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Why does OpenSSH debug2 handshake logging only on some logins, not on every login?
Running Ubuntu 18.04.1 LTS with package openssh-server 7.6p1-4ubuntu0.5
In /etc/ssh/sshd_config is set LogLevel DEBUG2.
I get the debug2 log message of the client MACs offering part of handshake:
May ...
user319783
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Keyboard mapping stops working -- how to debug?
I am alternating between two layouts, English and Hungarian (the latter has some accented characters).
The problem is that sometimes the Hungarian layout stops working, i.e. when I switch to it, the ...
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systemd debug (embedded case)
How to trace systemd unit files, to be specific, device unit files? I use 3.18 version of linux kernel. On my board after systemd has started, (mypartition).device runs and, I suppose, remounts the ...
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