Qt 4.8.7 May 2026

#include <QApplication> #include <QLabel> int main(int argc, char *argv[])

TEMPLATE = app QT += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets SOURCES += main.cpp Note: QT += widgets is ignored in Qt 4 – keep it for minimal cross-compatibility. | Feature | Qt 4.8.7 | Qt 5/6 | |-----------------------|-------------------------------|-----------------------------| | Widgets module | QtGui | QtWidgets | | QString vs QByteArray | Less efficient Unicode | Better Unicode handling | | OpenGL | QGLWidget | QOpenGLWidget | | Threading | QThread (old style) | Better thread affinity | | Signals/slots | Macro-based (still works) | New syntax (function ptr) | | QML | Qt Quick 1.x (obsolete) | Qt Quick 2.x+ | | Platform plugins | X11, Windows, Cocoa (limited) | Wayland, Direct2D, etc. | 6. Debugging & Common Pitfalls Crash on modern Linux? Qt 4.8.7 uses X11 and older fontconfig. Set: qt 4.8.7

QApplication app(argc, argv); QLabel label("Hello from Qt 4.8.7"); label.show(); return app.exec(); Debugging & Common Pitfalls Crash on modern Linux

FROM ubuntu:16.04 RUN apt-get update && apt-get install -y build-essential libgl1-mesa-dev ... ADD qt-everywhere-opensource-src-4.8.7.tar.gz /opt/ WORKDIR /opt/qt-everywhere-opensource-src-4.8.7 RUN ./configure -prefix /usr/local/qt487 ... && make -j4 && make install ADD qt-everywhere-opensource-src-4

configure -platform win32-g++ -prefix C:\Qt\4.8.7 mingw32-make mingw32-make install main.cpp