# Qt how to specify abi when compiling from source

• As I need the 3d features of qt but without using ANGLE, I compiled direct from the source as the tutorial of qt talks, but I noticed that after almost 3H compiling qt with jom it generated a 32bits version which is a problem because I need x64 for this project, so how to specify the abi? I compiled it as follows:

``````configure -debug-and-release -platform win32-msvc2017 -shared -opensource -opengl desktop -nomake examples -nomake tests

jom
``````

• Hi @Samuel-Ives,

did you open a 32 bit Visual Studio prompt by chance?

Regards

• Well I think the problem was this, it seems that the visual studio prompt I opened in the start menu was not specified as x86 or x64, it looks like they are in a subfolder called vc, I will try again with an x64 prompt and I will answer here if the problem was this.

When I run the jom command to compile, will it compile to the abi of the open prompt or will it compile to x64 if I open the prompt for x64?

• When I run the jom command to compile, will it compile to the abi of the open prompt or will it compile to x64 if I open the prompt for x64?

I really think that the resulting Qt library only depends on the compiler you are using. So if you have a x86 prompt, you get 32 bit libraries and programs; and for a x64 prompt you get 64 bit ones.

jom is just a replacement for nmake and calls the compiler and linker specified by the Visual Studio prompt.

PS: Don't forget to clean your build directory before rebuilding ;)

Regards

• @aha_1980

``````x86-windows-msvc2017-pe-64bit
``````

Thanks, it looks like the cause was actually the command prompt.