Qt Debugger: The GDB process terminated - c++

I am a freshman on Qt Designer.
Recently, I've used Qt creator create my own Qt project, which has been available to serial port. However, when I tried to debug my project, it always showed my with the following message, especially when there were breaks in my projects:
Error: The GDB process teminated.
I am very depressed. I have been getting stuck for several days.
If anyone could give me some instructions, more thanks would be given!
Thank you!

There can be different reasons, with different solutions;
(Below will list those most commonly causing this for me.)
#1 Toolchain
It's maybe related to your toolchain, for example I experienced similar issues, where I was compiling my code with latest MingW, but Qt was built with a little older MingW compiler.
I searched everywhere for the specific MingW, that which Qt was built with, but could not find that.
The only solution for me was to rebuild Qt from scratch (and fix all build errors).
#2 Permission
Another time, I was trying to attach debugger to an App running as root.
After running IDE (and by that the debugger) as root, things started to work.
But sometimes, following below #3 was required, too.
#3 Working Directory
Apps may load dependencies based on current-working-directory, for this case:
If you want to attach-debugger to already running root App:
We need to change the way IDE is launched, for example, open the terminal and cd to where the App requires us to (like directory containing the executable), then launch IDE from terminal (using it's path).
This may only be required when attaching to App(s) running as root, and even there not for all IDEs (but was required for QtCreator v4.x at least).
If you don't attach:
Simply change IDE configurations, I mean, most IDEs allow you to select working-directory (like QtCreator does), first do that and then start debugging.

Related

Configure kit for Qt automatically

SO!
Let's say I have a number of settings (GCC compiler 9.3.0 built from source, as the distribution I have to use has a very old one, along with environment setup) for a new Kit in QtCreator.
I have managed to setup an environment for compilation and execution of compiled binaries, and made a script to make it work (like qmake -nocache -recursive/make/sudo make install, direct execution of g++, and other stuff).
One thing that script can't do at the moment, is that it cannot create a kit for QtCreator with new compilers and environment being set as required, so after running a script, its user has to go through setting it up himself through GUI, which is bad, because this can cause misconfiguration.
This thing I'm trying to create is going to be used by around ~200 people in my company, so leaving readme.txt with instructions just doesn't go well enough for me - I don't want running around fixing missing "{" and "}" in Environment description in created Kits, and other stuff.
Are there ways to create Kits for QtCreator automatically from command line? Maybe, there's some files to edit?
I've looked into this one a few years back (I wanted to do something similar for registering Buildroot toolchains automatically in QtCreator), and I was unable to find an off the shelf solution. So i think there are 2 ways to implement this:
a) Implementing a command line utility the manipulate the ~/.config/QtProject/qtcreator/{toolchains,profiles}.xml files. Maybe by (re)using the existing C++ implementation within QtCreator, or just re-implement it ie. in Python. Back than I didn't start to work on this as there was no real business need.
b) Switching to qbs, as qbs has support for setting up toolchains from the command line ( see: https://doc.qt.io/qbs/cli-setup-toolchains.html)
If you decide to go with solution a), please let me know and maybe we can partner up to implement it.
Check out the command line sdktool bundled with QtCreator:
The SDK tool can be used to set up Qt versions, tool chains, devices
and kits in Qt Creator.
There still is a lot of knowledge about Qt Creator internals required
to use this tool!
I haven't tried it yet, but I did find the executable under Tools/QtCreator/libexec/qtcreator subdirectory of the Qt Creator installation directory. ./sdktool --help works for me under Linux.

Cannot run Qt Creator GUI outside of Qt. "The application was unable to start correctly (0xc000007b)" error

I downloaded C++ code from GitHub to tag images for training an object detector using Machine Learning.
Within Qt Creator 4.2.1 Based on Qt 5.8.0 (MSVC 2015, 32bit), I was able to compile and run the code. Unfortunately, I was not able to run the .exe outside of Qt Creator.
Initially, I received an error that
"The program can't start because libgcc_s_dw2-1.dll is missing".
Thanks to
QT The program can't start because libgcc_s_dw2-1.dll is missing, that was fixed easily by adding
"QMAKE_LFLAGS += -static"
to the .pro file. Now, when I run it I get
"The application was unable to start correctly (0xc000007b). Click OK to close the application."
I was able to reproduce the error using the simple "Hello World" default project that appears when you create a Qt Widget Application. This led me to believe something was wrong with my installation.
Based on the advice of this article: https://stackoverflow.com/questions/12099117/32-bit-qt-application-on-win-7-x64-wont-run-but-runs-fine-from-qt-creator, I used Dependency Walker to identify possible causes. I expected to see only a few items that I can follow up on. Instead, I received a list of close to 100 missing .dll files. All the files started with
"API-MS-WIN ###.DLL" or "EXT-MS ###.DLL"
where ### represent some additional text characters, for example;
"API-MS-WIN-SHCORE-STREAM-WINRT-L1-1-0.DLL"
I'm attaching a sample output.
Another suggestion was to copy over
libwinpthread-1.dll, libstdc++-6.dll, libgcc_s_dw2-1.dll.
That did not work either.
My next move was to simply get the latest version of QT and wish for the best. I installed Qt Creator 4.8.1 Based on At 5.12.0 (MSVC 2015, 32 bit). This time, I could not even get the code to run in the IDE. I received 1000+ error messages!
Based on advice from several pages, I added
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
to the .pro file and it still would not compile.
Also, I verified that the application is being built as a 32bit application. I'm running on a 64 bit Windows 10 system.
If anyone would like to take a crack at it to see if they can create a working .exe, here is the link: github.com/clavicule/BBTag
Qt provides a tool to copy the necessary dlls to the folder of your executable.
The tools is called windeployqt.exe and comes with your Qt installation. For me it is located at C:\Qt\5.9.1\msvc2015_64\bin\windeployqt.exe. You will have to look at your installation path and probably the msvc_32 folder to find it.
Then you go to the folder with your executable in it, oben a command prompt or powershell and execute path\to\windeployqt.exe yourProgram.exe and it will automatically copy the necessary dll files to this folder. Afterwards you can run your program without issues.
The official documentation for the tool can be found here.
Alternative 1: While developing you could use QtCreator which automatically adds the paths to the dlls when running your program - make sure to include them if you deploy your program!
Alternative 2: Add the path to the necessary dlls to your PATH variable. This isn't recommended either, since everyone who gets your program would have to do the same to run it.
I figured it out! My installation of Anaconda (a Python distribution popular for data science and machine learning) is the culprit.
From: #remy-lebeau
The application was unable to start correctly (0xc000007b)
The error:
"The application was unable to start correctly (0xc000007b) ..."
is a good indicator that the 32-bit app tried to load a 64-bit DLL. At first, this did not make sense since I verified many times that I was using the 32 bit version of Qt.
It turns out that the installation of the 64 bit version of Anaconda also contained many Qt5 dlls used for the PyQt5 package. Since the path to this folder came before the path to my c:\Qt...\bin folder, it was used in the build instead of the actual 32 bit version installed with Qt. This was not obvious because I was unaware of PyQt5 so I had no idea that it came with Anaconda. A simple reordering of the path entries using the System Environment Variables interface AND a system restart fixed the problem.
Silver lining: I now know C++ and designing GUIs w/ QT and PyQt5
Thanks #albertmand and #jwernerny

Debugging fails with QtCreator on OSX

I have OSX Yosemite 10.10.5, QtCreator 4.1.0, Qt 5.7.0 and Xcode 7.2.1.
If I write any native C++ program in QtCreator (console, gui - anything) I am unable to debug that program from QtCreator. Breakpoints get ignored, the program executes without pause and runs to completion no matter what I try.
I have tried the Xcode's LLDb, system GDB and Homebrew GDB as debuggers. the versions of GDB fail to start. Homebrew GDB has been codesigned.
This all used to (a few year back) just work beautifully and I am at a loss as to what might have changed.
Curiously, if I generate an exception inside the program - like accessing through a null pointer, the debugger shows me where this happens in just the way I would expect so, presumably, the debugger is running but simply treating me with complete disdain.
I know there are many versions of this question but none seem to address the problem adequately or offer workable solutions, or they apply to much older versions of the products.
Any suggestions?
This version of qtCreator (4.1.0) saw the return of the warning about having the build directory at the same level as the project directory. In Windows, this is done automatically. My mac installation does not get it right. (I may have messed a while back - cannot remember).
So - if the build directory is inside the project directory, debugging fails. Move the build directory up to the same level as the project directory and everything seems to work fine.
You can set the default build directory in the preferences/Build & Run dialogue. The path should start with ../
You will need to think about the folder structure before setting up the project unless you want build folders appearing in awkward places. So, a project folder structure like this is OK:
But one like this is not:
If this was already obvious to you, great. I have been messing with this for ages.
Many thanks to those who replied and anyone else who took the time to read the question. What helped e find it was the suggestion by #AlexanderVX that his setup was the same as mine but his worked. The only bit of my setup he could not see in the screenshots was the start of the build path. So that was the clue.

VSCode c++ configuring for vc toolchain

I'm trying to start a work in vscode , latest C++ plugin version supports ms debugger, so as I'm mostly working under windows it was a signal to try this.
c++ tools plugin from MS and cmake tools were installed.
my test project was however not built . the problem is clear , but I need an advice from experienced vscode users how to solve this right.
cmake doesn't see vc compiler.
(after using QtCreator) I expected that vscode could detect vc installation... however that's not so. ok, I have a two ways:
fill environment variables INCLUDE/LIB/PATH with a headers, libs and binaries
just run vcvarsall.bat x64
Second way is a simple and reliable. so final question is:
how to run .bat at the begining of vscode start?
(I don't mean write another bat/cmd, prepare the environment and run vscode inside the same script after that)
Although the question is fairly old, I'll try to give a useful answer, in case others stumble across, just like I did.
I believe what you are trying to achieve is not possible. Code inherits the environment it was started with. If you did not launch it from a developer command prompt, you will not be able build and debug. (Building might be possible if every task first starts the vcvarsall.bat, but that slows things down by a lot. Debugging I think will still not work.)
If you are willing to, you can check out vector-of-bools CMake Tools extension which does build automation as well as automatic MSVC detection. It builds using CMake (thus you need to write your build scripts using CMake), but it will take care of building just by pressing F7, like what most VS users are familiar with.

Juno CDT plugin failing to run a C++ application

I have a simple mixed C/C++ application (OpenGL example) which I have successfully built using Eclipse CDT in Juno (MinGW toolchain).
I can run this application fine by hand from a Win7 command console, but it seems to rarely work when running from Eclipse's "Run as" menu. Whether it works or not seems down to seemingly unrelated changes in the code, and I get nothing of interest on the Eclipse run console (just a <terminated> status) even when no code near the start of the application has changed.
I'd like to and it sometimes I can work around this for now, but would be good to get this working if anyone has any ideas - it seems an essential stepping stone to get the debug environment working in Eclipse.
EDIT Side thought - eclipse seems awfully thin on debug diagnostics when something like this fails. If there is any way to turn on more debug I'd welcome the knowledge =)
Resolved - the issue is down to the path being given to the application, or more specifically the OS launcher (so it can find the DLLs it needs).
Even through the default "run" config claims to inherit the parent environment, it doesn't seem to get the same environment as the Win7 command console. I had to manually edit the "Run as" config in Eclipse to have a custom PATH environment variable containing the directories I needed (MinGW/bin, and a directory containing some custom DLLs).
Cheers, Iso