Library 'vulkan' is not defined. with QMake, clang6, Qt 5.10.1

[Hallot]

Hi,

I've just upgraded to clang6, and my qmake projects with Qt 5.10.1 all fail to configure now with the error:
"Library 'vulkan' is not defined."

I have no issues with GCC 7.3 or with CMake based projects.

I've noticed that "#define QT_FEATURE_vulkan 1" has been set to 1 now, where it was -1 before, but even changing it to -1 manually does not seem to fix the issue.

Any help is appreciated,
Thanks.

[SGaist]

Hi,

Do you mean that the vulkan option gets activated only when building with clang ?

[Hallot]

I don't think the option is activated only with Clang, the macro I talked about is a system include and thus would not change between compilers.
Maybe there's something missing in the clang toolchain? Or maybe it's an option that Clang triggers and not GCC.
I am not sure really. And I'm not sure how to check whether the Vulkan option is activated with GCC.

[SGaist]

Can you explain exactly how you setup things ?

[geomojo]

I came across this error too (haven't looked for a work around yet). Anyway, SGaist asked how to set things up to get this error, so thought I'd share...

1. Start a VS command prompt (I'm using VS2017)
   C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\Tools\LaunchDevCmd.bat

2. Set QMAKESPEC
   set QMAKESPEC=winrt-x64-msvc2017

3. Run qmake
   qmake -tp vc

I get "Project ERROR: Library 'vulkan' is not defined". This has something to do with the "winrt-x64-msvc2017" part (I think). I'm able to run qmake OK with other values for QMAKESPEC.

[SGaist]

Based on this blog post Vulkan is not available for WinRT in Qt 5.10.

[Hallot]

Yes, I've managed to solved this by correctly setting the makespec as well. I think it was using old spec files for a previous Qt/Clang version which caused the non-obvious issue.

Thanks for the help.