I am currently running a ros node with launch-prefix="xterm -e gdb --args" attribute as described at here to debug with gdb.
My current terminal emulator is terminator.
How can I run the node on my preferred terminal emulator terminator?
I tried to change launch-prefix as launch-prefix="terminator -e gdb --args" but it did not work.
Related
I'm receiving this gdb error on any code I try to debug any program with gdb. Here's the simplest process that reproduces the error
Create a main.cpp file with this content:
int main(){
return 0;
}
Run g++ -g main.cpp
Run gdb a.out
Inside gdb set a break point at line 2 with break 2
In gdb run the program with run
Output:
Starting program: /tmp/test/a.out
During startup program exited normally.
This is all done with gdb on the command line. I've tried using g++ and gcc with the same result. I'm not really sure where to go from here.
gdb version = 9.2
g++ version = 9.3.0
EDIT: I figured out what is causing the issue, but not how to fix it. The issue seems to be something related to my SHELL variable. I'm currently using xonsh as my shell but when I set my SHELL environment variable back to /bin/bash everything works as expected. Is there anything I can do to fix this while using xonsh? Should I report this to xonsh, gdb, both or neither?
I'm currently using xonsh as my shell but when I set my SHELL environment variable back to /bin/bash everything works as expected. Is there anything I can do to fix this while using xonsh? Should I report this to xonsh, gdb, both or neither?
This might be your xonsh startup problem, or it might be xonsh problem, or it could be that xonsh doesn't do what GDB expects it to do.
Normally, GDB forks / execs $SHELL -c "/path/to/your/exe $args" and expects the $SHELL to exec your program (this is done so shell redirection still works under GDB).
Only after that exec will GDB start setting breakpoints, etc.
If you have some xonsh init-file, which e.g. causes xonsh to exec something else, things could go bad. So I suggest trying to remove any such ~/.xonshrc or whatever it's called file, and seeing whether that fixes the problem.
If it doesn't, it could be that xonsh e.g. forks and execs your binary in a child (grandchild of GDB) instead of doing it directly, or it could be that xonsh doesn't understand the -c ... syntax.
If you don't care about redirection, you could also ask GDB to not use $SHELL at all: set startup-with-shell off. Documentation.
I have a setup with openocd and arm-none-eabi-gdb and I'm trying to debug a FreeRTOS fw.
I start openocd with:
openocd -f /usr/local/share/openocd/scripts/board/stm32f0discovery.cfg -c "stm32f0x.cpu configure -rtos auto"
That command works fine.
Then I run arm-none-eabi-gdb -tui and at the end of my .gdbinit I have:
target remote localhost:3333
monitor reset halt
file build/fw.elf
load
continue
focus next
But when I try to stop <ctrl>-c and start continue my fw all I get is the error:
Cannot execute this command without a live selected thread.
What am I missing?
I'm using a JLink Base debug probe.
My case is a bit different than yours, with a setup using QtCreator and its Baremetal plugin, but found a bug report where they state a workaround:
https://bugreports.qt.io/browse/QTCREATORBUG-18436
The workaround is pretty easy:
in GDB Init commands add "info threads" after load command. It fixes issue.
I tried it, and it worked, the error message was removed, and now I can see the different tasks in FreeRTOS.
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'm trying to run my program TestApc via gdb and get useful data when my program crash with back trace command ("bt" command).
I wrote a bash script , which look like:
#!/bin/bash
gdb -ex=r --args ./TestApc
When the program crash, I can't type the "bt" command (because I get out from the gdb console)
Is there a way to stay on gdb after the crash ?
I'd like to have gdb immediately run the executable, as if I'd typed "run"
(motivation: I dislike typing "run").
One way is to pipe the command to gdb like this:
$ echo run | gdb myApp
But the problem with this approach is that you lose interactivity with gdb,
eg. if a breakpoint triggers or myApp crashes, gdb quits.
This method is discussed here.
Looking at the options in --help, I don't see a way to do this, but perhaps I'm missing something.
gdb -ex run ./a.out
If you need to pass arguments to a.out:
gdb -ex run --args ./a.out arg1 arg2 ...
EDIT:
Orion says this doesn't work on Mac OSX.
The -ex flag has been available since GDB-6.4 (released in 2005), but OSX uses Apple's fork of GDB, and the latest XCode for Leopard contains GDB 6.3.50-20050815 (Apple version gdb-967), so you are out of luck.
Building current GDB-7.0.1 release is one possible solution. Just be sure to read this.
I would use a gdb-script:
gdb -x your-script
where your-script contains something like:
file a.out
b main
r
afterwards you have the normal interactive gdb prompt
EDIT:
here is an optimization for the truly lazy:
save the script as .gdbinit in the working directory.
Afterwards you simply run gdb as
gdb
... and gdb automatically loads and executes the content of .gdbinit.
(echo r ; cat) | gdb a.out
The cat allows you keep typing after gdb breaks.
start command
This command is another good option:
gdb -ex start --args ./a.out arg1 arg2
It is like run, but also sets a temporary breakpoint at main and stops there.
This temporary breakpoint is deactivated once it is hit.
starti
There is also a related starti which starts the program and stops at the very first instruction instead, see also: Stopping at the first machine code instruction in GDB
Great when you are doing some low level stuff.
gdb -x <(echo run) --args $program $args