`Project ERROR: Unknown module(s) in QT: gui` Even when QtGui not configured in

[patrickkidd]

It looks like QT += gui is added implicitly in qmake projects. At least in 5.15.2. This throws the error: Project ERROR: Unknown module(s) in QT: gui. Adding QT -= gui fixes the problem. But my .pro files are auto-generated (by sip) so I can't add a line to the end of them. So how is it possible to prevent Qt from implicitly adding gui to QT when QtGui is not configured to build?

configure line:

./configure -opensource -confirm-license -release -nomake examples -nomake tests -prefix $HOME/qt -no-feature-concurrent -no-feature-dbus -no-feature-network -no-feature-sql -no-feature-testlib -no-feature-xml -no-gif -no-libjpeg -no-mtdev -no-sql-db2 -no-sql-ibase -no-sql-mysql -no-xcb -qt-freetype -no-fontconfig -no-harfbuzz -no-xcb-xlib -no-cups -no-iconv -no-icu -no-eglfs -no-gui -no-widgets -no-feature-gui -skip qtgui -skip qtactiveqt -skip qtcanvas3d -skip qtgamepad -skip qtremoteobjects -skip qtscript -skip qtspeech -skip qtvirtualkeyboard -skip qtwayland -skip qtwebview -skip qtnetwork

notice: -no-gui -no-widgets -no-feature-gui -skip qtgui

Example qmake file that breaks:

TEMPLATE = app
SOURCES = main.cpp

And file that works:

TEMPLATE = app
SOURCES = main.cpp
QT -= gui

At the end of the day, all I'm trying to do is build a qt make and lib that has qtcore and nothing else. For backward compatibility I just need to use a library that uses qbytearray and no other classes. If there is a cleaner way to configure qt that would be great. But the configure line above is the best I can come up with.

[JKSH]

@patrickkidd said in `Project ERROR: Unknown module(s) in QT: gui` Even when QtGui not configured in:

It looks like QT += gui is added implicitly in qmake projects.

Yes, this is specified in the documentation: https://doc.qt.io/qt-6/qmake-variable-reference.html#qt

But my .pro files are auto-generated (by sip) so I can't add a line to the end of them.
So how is it possible to prevent Qt from implicitly adding gui to QT when QtGui is not configured to build?

You have 2 options:

• Don't skip the Qt GUI module, OR
• Modify the qmake source code before building, to stop it from adding gui by default (I don't know where this code is)

[kkoehne]

@JKSH is right, this is documented behavior, so the generator should be ideally adapted.

The code that adds core and gui by default to QT is in mkspecs/features/spec_pre.prf . You could modify this file directly (breaking behavior for all other qmake apps), set up your own profile / .prf file, or reset the content of QT on the command line:

qmake -after QT=core