How to reproduce

• Build qtbase statically with qmake or CMake. I've used a prefix build if that makes a difference.
• Build qtsvg against qtbase.
• Build qtsvg's tests.

/usr/bin/ld: /home/jobor/Qt/dev-qmake-static/lib/libQt6Gui.a(qplatformfontdatabase.o): in function `lcQpaFonts()':
/home/jobor/dev/qt/dev/qtbase/src/gui/text/qplatformfontdatabase.cpp:56: multiple definition of `lcQpaFonts()'; /home/jobor/Qt/dev-qmake-static/lib/libQt6ThemeSupport.a(qgenericunixthemes.o):/home/jobor/dev/qt/dev/qtbase/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp:79: first defined here