"Unhandled exception: Microsoft C++ exception: std::bad_alloc" only appears on Debug

[H4x0r-000]

I get this exception whenever I startup the program in debug mode, even if its just the default code. But every other mode works without any errors, my question here: I it still safe to use? or did I miss something?

PS: I did not make an issue, because I am not sure if it is one.

[prothegee]

Seems like some shared object *.dll not included. If you compiled manually drogon project to create lib/ctl might not work when build type is not same, unless you use vcpkg or somethin that include release & debug version.

---

1

You may check your DCMAKE_BUILD_TYPE arg first, is it on Debug or Release,
then try recompile your project with which build type you configured.

---

2

If you're using vcpkg, you can add those path or manually on your system environment

be sure some dependencies are installed, example to install it
vcpkg install drogon[core,ctl,sqlite3,postgres,orm]:x64-windows you may also looking for jsoncpp, openssl, zlib, c-ares & brotli

or just do vcpkg search to check whats available for drogon options.

double check if those path are included
commonly what you need to include:
[vcpkg_root]/installed/<your_triplet>/include
[vcpkg_root]/installed/<your_triplet>/lib
[vcpkg_root]/installed/<your_triplet>/share
[vcpkg_root]/installed/<your_triplet>/tools/drogon

and some debug directories when you need it.

---

3

there's also a way to just used custom path system variable, and let cmake configure that,
just be sure that you regist that path on your system variable, says:
variable name = VCPKG_DIR
variable value = <path/to_your/vcpkg>
and so on...

later on on your project, add these to your CMakeLists.txt

...
include(CheckIncludeFileCXX)
include("$ENV{VCPKG_DIR}/scripts/buildsystems/vcpkg.cmake")
...
add_executable(${PROJECT_NAME} main.cc)
...
target_include_directories(${PROJECT_NAME}
    PRIVATE
    # vcpkg
    "$ENV{VCPKG_INCLUDE}"
    "$ENV{VCPKG_LIB}"
    "$ENV{VCPKG_SHARE}"
)
...

---

4

If you still encountered error, access violation or etc that came from C:\Windows\System32 or C:\Windows\SysWow64
after those steps,

run repair from your visual studio installer, restart your system.

Try to delete your build/out directory, configure your cmake then build it again and test to debug/run it

note

be sure your cmake generator is not default visual studio,
the behaviour is not same as make/nmake generator

---

5

Still had exception? Don't have any idea again, I haven't face more than that.

[sbrajchuk]

I had the same exception on Debug with this code:

#include <drogon/drogon.h>
int main() {
    //Set HTTP listener address and port
    drogon::app().addListener("0.0.0.0",80);
    //Load config file
    //drogon::app().loadConfigFile("../config.json");
    //Run HTTP framework,the method will block in the internal event loop
    drogon::app().run();
    return 0;
}

I'm using Visual Studio 2022.
Installed drogon via vcpkg.
Exception dissapeared after loading correct dlls.
At first I've used dlls from d:\Dev\vcpkg\installed\x64-windows\bin\ and had std::bad_alloc.
Then I've used dlls from d:\Dev\vcpkg\installed\x64-windows\debug\bin\ and exception disappeared.

If I understand correctly, drogon.dll from x64-windows\bin\ uses different ABI for std:string and that cause the exception.

[Ayman250]

I'm running into the same issue. How change the dlls that are loaded?

[sbrajchuk]

I change DLLs by adjusting the PATH environment variable. Specifically, for the debug configuration, I append 'D:\Dev\vcpkg\installed\x64-windows\debug\bin' to the PATH, and for the release configuration, I append 'D:\Dev\vcpkg\installed\x64-windows\bin'.

[Ayman250]

Thanks. I tried that and I'm still having the same issue. I initially had both in PATH as per the installation instructions. I removed D:\Dev\vcpkg\installed\x64-windows\bin, but I'm still having the same problem.

[sbrajchuk]

Restarting Visual Studio is necessary to apply the changes made to the environment variables.