Project not building on windows

[Creaperdown]

Hey, I am currently working on a project, which works all fine on linux, but doesnt seem to build on windows.

The error messages I get are:

I wouldnt exactly know what code to provide. What I am building is this: https://github.com/Librum-Reader/Librum.
Does anyone have an idea why these errors could occur?

I noticed that it shows me (at the bottom of the error message), that there is an undefined reference to my signals, which I find weird, since I use the Q_OBJECT macro in all my classes

Thanks in advance

[Christian Ehrlicher]

Wouldn't it be better to ask the author of the project?

[Creaperdown]

@Christian-Ehrlicher Well, I am the author

[kkoehne]

"undefined reference" errors on Windows are usually related to the fact that, on Windows, you have to explicitly export and import symbols if these symbols are used across library/module boundaries.

See also https://doc.qt.io/qt-6/sharedlibrary.html

[Creaperdown]

@kkoehne I see, I'll try this. Is it generally enough to put Q_DECL_EXPORT infront of every class I want to use from another binary?

[SGaist]

Hi,

Not Q_DECL_EXPORT but yes you have to export all the classes you want to use from your library.

See how it is done in the documentation @kkoehne linked.

[ali-aydin]

Hi,
it maybe depend on your access permission to Storage

[SGaist]

@ali-aydin said in Project not building on windows:

Hi,
it maybe depend on your access permission to Storage

No it's not. If it was access permission related, @Creaperdown wouldn't be able to build the library in the first place.

[Creaperdown]

@kkoehne I've tried following the docs on a small project I set up (which has the same issue, I think my other project has) but it still doesnt work. https://github.com/Creapermann/Temp

[kkoehne]

@Creaperdown , I just successfully compiled the latest HEAD (d5e98b8c6cc17abe) of your repository on Windows, with MinGW and MSVC:

C:\dev\tmp\Temp>cmake -B mingw-build -GNinja -DCMAKE_PREFIX_PATH=C:\Qt\6.3.1\mingw_64 .
-- The CXX compiler identification is GNU 11.2.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Qt/Tools/mingw1120_64/bin/c++.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE
-- Found WrapVulkanHeaders: C:/VulkanSDK/1.2.176.1/Include
-- Configuring done
-- Generating done
-- Build files have been written to: C:/dev/tmp/Temp/mingw-build

C:\dev\tmp\Temp>cmake --build mingw-build
[21/21] Linking CXX executable appTesting.exe

What compiler are you using, and what is the exact compiler output you get?

[Creaperdown]

@kkoehne I am using the same setup you do. I have Qt 6.3.1 and am using mingw_64. When I am running the exact same command you do, in the command line, I get following error:

cmake -B mingw-build -GNinja -DCMAKE_PREFIX_PATH=C:\Qt\6.3.1\mingw_64 .
-- The CXX compiler identification is GNU 6.3.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/MinGW/bin/c++.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:22 (find_package):
  Could not find a configuration file for package "Qt6" that is compatible
  with requested version "6.2".

  The following configuration files were considered but not accepted:

    C:/Qt/6.3.1/mingw_64/lib/cmake/Qt6/Qt6Config.cmake, version: 6.3.1 (64bit)



-- Configuring incomplete, errors occurred!
See also "C:/Users/prtnp/Programming/Temp/Temp/mingw-build/CMakeFiles/CMakeOutput.log".

Do you have an idea why this doesnt work? Looking around I only find that not using CMAKE_PREFIX_PATH could cause this, but I do.

Also, when using QtCreator, it compiles but it doesnt run. Does the application run for you?

[Creaperdown]

Also, I've realized I am using mingw_64, which exports all symbols by default, so I don't think that exporting the symbols is the problem. Does anyone have another idea?

[cristian-adam]

In your compilation example you have:

-- The CXX compiler identification is GNU 6.3.0

Please use a newer MinGW. The one from Qt SDK should be 11.2.0.

In your temp project you have:

find_package(Qt6 6.2 COMPONENTS Quick REQUIRED)

Please remove the 6.2 part, which doesn't play well with Qt version 6.3.1 given via -DCMAKE_PREFIX_PATH=C:\Qt\6.3.1\mingw_64.

[kkoehne]

@cristian-adam said in Project not building on windows:

Please remove the 6.2 part, which doesn't play well with Qt version 6.3.1 given via -DCMAKE_PREFIX_PATH=C:\Qt\6.3.1\mingw_64.

I think this should actually be fine, because 6.3.1 is compatible with 6.2, and no EXACT is set.

But yes, the GCC compiler version is too old.