Building Qt 5.14.0 on Windows 10 with Visual Studio 2019

Time for another short guidance on how to build your own copy of the Qt framework from source.

I’ve upgraded to Visual Studio Community Edition 2019 (Version 16.3.10) in the meantime and will now also use the current Qt 5.14.0 release instead of the 5.12.x LTS line.

As mentioned before, building Qt from source by yourself may not be neccessary when you run up-to-date versions of the OS and IDE: Just install it via the online installer from the Qt site. I do this mostly out of habit and to keep in training 😉

Anyways, if you’re still with me, I guess you also know what/why you want it; so, on with the show.

  1. Microsoft Visual Studio 2019 (Community Edition) — install it at least with the C++ Desktop workload, the C++ toolset and the Windows SDK.
  2. Perl/ActivePerl — it should be put in PATH for the command prompt build environment after installation.
  3. Python — it should be put in PATH for the command prompt build environment after installation.

Official page: Qt 5 for Windows - Requirements: Building from Source.

Download

The shortcut to version Qt 5.14.0 is http://download.qt.io/official_releases/qt/5.14/5.14.0/single/qt-everywhere-src-5.14.0.zip (ca. 800 MByte).

The way to get to the download links for the offline sources from the homepage is well hidden, and the ways to get there change with every redesign every couple of months… But the final URL still works: https://www.qt.io/offline-installers/. And there: Source packages & Other releases → “The source code is available: For Windows users as a single zip file”.

Extract

Extract it to an appropriate place for you (e.g. I use C:\devel\ext\Qt\5.14.0\ in my environment).
If your extraction tool of choice puts it into sub-directories like qt-everywhere-opensource-src-5.14.0, then move the content of it up to the root level and delete this now empty folder(s).

Build

The next steps describe how you build 64-bit DLLs with Visual Studio 2019; for 32-bit files, or static libraries, or…, adjust the paths/names/options accordingly to your needs!

  1. Open the x64 Native Tools Command Prompt for VS 2019 (you can find it in the start menu entry ‘Visual Studio 2019’) and navigate to C:\devel\ext\Qt\5.14.0\ (or whatever your chosen location is…).

  2. Run Qt’s configure.bat from there to prepare the build.

    The following list of options is a setup that works for me, for my current projects; you may need different features enabled/disabled, etc.
    Run configure -h to get the full list of options.

    Note: I removed now several -no-… options (e.g. -no-opengl, -no-openssl etc.) that I used before here, because on the first attempt to build, the run stopped with a fatal link error after some hours (*groan*). Might have been a coincidence, but when doing it again, without these exclusions, it completed successfully (but also took a lot longer to build than before).

    Argument Comment
    -confirm-license Automatically acknowledge the license.
    -prefix <DIR> The deployment directory, as seen on the target device.
    <DIR> is a full path like C:\devel\ext\Qt\5.14.0\_64DLL
    -release Release-only build (Build Qt with debugging turned off).
    -opensource Build the Open-Source Edition of Qt.
    -silent Reduce the build output so that warnings and errors can be seen more easily.
    -shared Build shared Qt libraries (creating DLLs).
    -platform win32-msvc Use Microsoft Visual C++.
    -mp Use multiple processors for compilation (Microsoft Visual C++ only).
    -make tools For lupdate/linguist/lrelease and so on.
    -nomake examples Exclude examples.
    -nomake tests Exclude tests.

    That means, you’ll execute a long command, like:

    C:\devel\ext\Qt\5.14.0\> configure.bat -confirm-license -prefix C:\devel\ext\Qt\5.14.0\_64DLL -release ...
    

    `

  3. Type nmake to kick-off the building process; this will take quite a while (on my current, not very modern setup (Intel Core i5-760, 8 GB): Four to five hours…)
    To clean up (e.g. after a failed build, before trying again), do nmake clean (or nmake distclean).

  4. Type nmake install to move the built binaries to the target directory.

That’s it!