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How to rebuild just part of Qt 5 to test a bug fix?

  • I have a fix for a bug in Qt 5.6.1 that I'd like to test. The file I'm changing is qtbase\src\gui\painting\qpdf.cpp.

    How do I go about rebuilding the minimum necessary (I assume QtGui)? Or do I have to start with a fresh download of Qt code, make my edit, then build all of Qt?

    In case it matters, here's my configure when I originally built Qt 5.6.1 from source:

    configure -prefix %CD%\qtbase -developer-build -opensource -opengl desktop -nomake tests -no-compile-examples -icu -plugin-sql-sqlite -platform win32-msvc2013 -confirm-license -qtlibinfix _fmosoft

  • Lifetime Qt Champion


    Just build qtbase that will be enough.

    I recommend using an out of source build so you can fiddle with your sources without have all the generated stuff in it.

  • Thanks @SGaist, that worked beautifully - about 1 minute instead of 11 hours! For those like me who aren't too sure what they're doing, a few more details for Windows: I opened a command prompt the same way as when I initially built Qt 5. I cd to the qtbase directory, run


    and about 1 minute later I could run my app and step into the Qt code, and see how my fix worked.

  • Lifetime Qt Champion

    You're welcome !

    Just in case, when needing to build Qt, you can also avoid modules you won't use that are pretty heavy to build like QtWebEngine or QtWebKit.

    In any case, since you have it running now, please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found :)

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