I am using gdb 7.7.1 on ubuntu, GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.2) 7.7.1.
My terminal is Konsole 2.13.2.
The problem I am having is, when I go to the TUI mode, after one or two debugger sessions - session, I mean, set breakpoint, run, step over a while and finally kill it by "kill" command - the output starts messed up. Supposedly each output should go to a new line, but now they just all scramble, one immediately after another one.
I attach a screenshot.
I have to quit GDB, open a new terminal tab and start gdb again.
I tried "ctrl-x-a" back and forth, does not help; neither does "ctrl-l".
A while back, I was using another terminal, it also had this problem.
Any help is appreciated.
It appears that your tty settings changed, in much the same way that tty -onlcr might change them (tty onlcr restores the default). Perhaps the code you're debugging changes tty settings, and doesn't get a chance to restore them because of a crash.
As suggested in a comment, using a separate window might provide a workaround.
I have the newest (2020.3 EAP ATM) version of CLion and I currently use it to remote debug a program on an embedded target (linux-mipsel).
Everything works as expected, after a bit of configuration, using self-built cross-toolchain and gdbserver.
My only problem is hitting the "red square" to stop execution will neither kill the running program nor gdbserver itself.
This means next iteration of edit-compile-debug cycle I will have two copies of both (I can get more, if I insist) which will not work as each tries to open the same resources (e.g.: a serial port) concurrently.
I have to manually log into target and kill the offending processes.
Am I missing something, is it a known bug or what?
Small update:
gdbserver is actually killed (does not show in ps ax) but underlying program (debugee) is still there. I am unsure why I was convinced otherwise, my bad.
This is a known issue and will hopefully be fixed soon.
Here is the link to the youtrack issue: https://youtrack.jetbrains.com/issue/CPP-20346
You could try the suggested workarounds:
Add pre-deploy configuration which kills running instances of the program
Follow the instructions for the gdb configuration in the comments:
GDB Server: /bin/bash
GDB Server args: -c "gdbserver :1234 /home/pi/myapp; pkill -e myapp"
The second config did not work for me, so I added the execution of an external tool where I run in /bin/bash the command -c "pkill -e myapp || true". The true is mandatory to avoid errors if the program is not running.
Background
I am currently trying to build an autonomous drone using ROS on my Rapsberry Pi which is running an Ubuntu MATE 16.04 LTS. Solving the Computer Vision problem of recognising red circles as of now.
Specific Problem
I am constantly getting the error I get in this question. To help me solve this, I have decided to use gdb. However, the command rosrun --prefix 'gdb run --args' zlab_drone vdstab does not seem to be working for me. zlab_drone is the name of the package and vdstab is the name of the executable I am trying to run. Since this is inside a ROS environment, I have grabbed the syntax from here, and used the suggestions in this question.
When I invoke this command, even with tui, I get a SIGSEGV and when I invoke list inside gdb itself, the program does not stay at a particular point and keeps listing a different line till it is out of range. This is quite a weird issue.
I managed to make it work without this issue earlier by using a different command, I reckon. I just cannot remember how I made it work last time.
Well, in the link you mentioned, it states clear that you should use either :
launch-prefix="xterm -e gdb --args" : run your node in a gdb in a separate xterm window, manually type run to start it
or :
launch-prefix="gdb -ex run --args" : run your node in gdb in the same xterm as your launch without having to type run to start it
So, it really looks like you missed an -ex as #ks1322 suggeseted in the comments or just type run to start the debug process.
I found out about this exclusive bug that relates to Raspberry Pi's solely. Basically the solution involves, as quoted by Peter Bennet:
There is a workaround. Start the program, then from another command
prompt or from an ssh remote login, use gdp -p xxxxx where xxxxx is
the process number. This works without crashing. If you need to debug
something that happens before you can get in from another command
prompt, add to the program a command that stops process at the
beginning of main, for example a call to gets, which will wait for you
to press enter before continuing.
I recently reinstalled Cygwin on my computer in order to get access to several command line elements that I was missing. I have never had previous difficulty with Cygwin, but after this reinstallation, an error message continues to appear after (almost) each command entered. For instance:
-bash-4.1$ wc m1.txt
3 [main] bash 2216 child_info_fork::abort: data segment start: parent(0x26D000) != child(0x38D000)
-bash: fork: retry: Resource temporarily unavailable
2013930 4027950 74968256 m1.txt
Generally, the command still runs (as seen above), but not always. Occasionally, the 'error' message occurs several times in a row (the initial number "3" will then change to a "4" or "2", notably if I start a second Cygwin window.
Also, as soon as I start up Cygwin, I get the following message before the prompt:
3 [main] bash 6140 child_info_fork::abort: data segment start: parent(0x26D000) != child(0x36D000)
-bash: fork: retry: Resource temporarily unavailable
-bash: fork: Resource temporarily unavailable
-bash-4.1$
At the moment, I am debating whether to uninstall/reinstall Cygwin again or just live with the error messages, but I was curious if there might be an issue that I am unaware of.
(assuming Cygwin is installed at C:\Cygwin):
Open Task Manager and close any processes that look to be Cygwin related.
Open C:\Cygwin\bin in Windows Explorer
Verify that dash.exe, ash.exe, rebase.exe, and rebaseall exist in this folder
If any of them are missing, re-run Cygwin setup and select the dash, ash, and rebase packages
right-click your C:\Cygwin folder, uncheck Read-only (if its checked), and press OK.
When an error about not being able to switch some files comes up, select "Ignore All". Wait for this process to complete.
Browse to C:\Cygwin\bin in Windows Explorer
Right click dash.exe and click "Run as Administrator". A command Prompt should appear with nothing but a $
Type /usr/bin/rebaseall -v, hit enter, and wait for the process to complete.
If you get errors about Cygwin processes running, try Step 1 again. If that still doesn't work, Restart your computer into safe mode and try these steps again.
A commenter noted that, depending on your settings, you may have to type cd /usr/bin && ./rebaseall -v instead.
Try opening Cygwin again.
This process worked for me. I hope it works for you guys too.
Source: http://cygwin.wikia.com/wiki/Rebaseall
I would like to add the following to the above answers, as it is what I had to do after reinstalling Cygwin:
Navigate to the "/usr/bin" directory (usually, C:\cygwin\bin) and right click, Run as Administrator the file: dash.exe
Then, at the $ prompt type the following, hitting enter after each line:
cd /usr/bin/
/usr/bin/peflags * -d 1
/usr/bin/rebaseall -v
What it does is, it marks the dll's as "rebase-able," and then rebases them. You have to have peflags.exe in addition to the above files (in previous answers). You may have to restart windows after doing this and you will definitely need to make sure that there are no processes nor services belonging to cygwin running. (Use task manager, kill any related processes, and then under the services tab look for any service starting with CYG and stop it.)
After doing this, I was able to get cygwin to run without any errors about dll's being loaded to the wrong addresses aka fork errors, etc.
I hope that this helps others, as it was a pain to find.
SOURCE: http://www.cygwin.com/faq.html#faq.using.fixing-fork-failures
and the rebase README file.
To add on to other answers here, we ran into the same issue but could not run the rebase command from the ash or dash shell. However, when launching the command from the Windows cmd shell, the following worked.
cmd /c "C:\cygwin64\bin\ash.exe /usr/rebaseall -v"
-v is to get verbose output
I found another information here :
http://cygwin.com/ml/cygwin/2014-02/msg00531.html
You have to delete the database at
/etc/rebase.db* and do in a "ash" windows :
peflags * -d 1
rebaseall
It works for me on 2 servers.
I solved this problem by restarting my computer. Probably installed a driver update and kept using sleep instead of shutting down.
Experienced the same issue when loading Cygwin with cygiconv-2.dll forking and not loading successfully in the Cygwin terminal, but after turning off my AntiVirus (it was specifically Ad-aware), the issue resolved, and Cygwin worked properly.
In case you are using babun's Cygwin, after rebaseall, try launching Cygwin by executing .babun\cygwin\cygwin.bat in a Windows command prompt or Windows explorer.
This works for me (while launching babun's default console - mintty results in fork error).
I had the error on win10 and i was trying to rebase to c: before install.
then i saw that the installer was installing it instead to c:/Users/myuser
so i was coping all files from c:/Users/myuser to c:.badun
and then restart plus open badun.bat
not shure if this was wise its now duplicated XD... but then it worked again.
Rebaseing didn't help in my case. In addition to what other people suggested, I noticed that reducing the length of PATH environment variable fixed the issue for me (and for other people as well as can be seen from this answer).
This issue is intermittent in nature & I found this issue when there is network is too slow to connect to remote machine on AWS.... I have Shell script that runs through Gitbash shell & it connects to AWS EC2 instance with ssh..... Most of the time, it ran correctly but 2 out 100 times it get into this issue bash: fork: retry: Resource temporarily unavailable .... Killing the MSYS2 terminal from task manager helps to overcome with this issue....
Negative side is you need to run the scripts from the beginning...
I had the same issue on Windows 10 and the mobaxterm app (which uses cygwin) and I tried all of answers listed here however for me, the solution was to simply delete the "CryptoPro CSP" application.
I started facing this problem after upgrading to windows 10. As of now I do not see that any of the above method working.
What I am noticing is that if you start cygwin with admin right (right click and say "run as admin") then it works fine.
Or you open cmd as administrator and then launch cygwin from there, then also it runs fine.
Just reinstall cygwin and select TCL and activate EXPECT
when I run gdbserver on uclinux target device blackfin bfin537/stamp it work perfectly but it always generates annoying output
Request to get for unknown register 232
Request to get for unknown register 236
it is extremely annoying since each step out or step in gdb client results several of that error on the output screen terminal RS232 I was recommended to change the bfin compiler version and rebuild gdb server with different version of uclinux ,.... none of them worked and even compiling my code with different versions of bfin-uclinux-gcc didn't solve my problem.
I decided to recompile gdbserver.c and eliminate the line that generates the error but in fact that line does not exists in any of the gdbserver related files for compiling.
I decided to suppress the stderr output of gdb server by running gdbserver :3298 process 1>/dev/null 2>/dev/null but this didn't solve it
how can I configure my gdb client to asks for specific registers (bfin-uclinux-gdb) related to bfin537-stamp?
I think this error originates somewhere else in uclinux system background system processes.
I want to find which process writes in stderr,stdout which I am unaware of It and I want to suppress its outputs?
Shall I change something in the busybox shell or /bin/bash to eliminates all stderr outputs
which means if I send all the parent shell output or stderr to /dev/null
Thanks