Error during installation: ‘class QComboBox’ has no member named ‘setPlaceholderText’

[Griffin]

Hi everyone,

I'm following the instructions here to install Dolphin on Ubuntu, and I'm encountering this error on the final step when I run "sudo make install":

Code:

[ 83%] Building CXX object Source/Core/DolphinQt/CMakeFiles/dolphin-emu.dir/Debugger/MemoryWidget.cpp.o
/home/griffin/dolphin-emu/Source/Core/DolphinQt/Debugger/MemoryWidget.cpp: In member function ‘void MemoryWidget::CreateWidgets()’:
/home/griffin/dolphin-emu/Source/Core/DolphinQt/Debugger/MemoryWidget.cpp:108:21: error: ‘class QComboBox’ has no member named ‘setPlaceholderText’
 108 |   m_search_address->setPlaceholderText(tr("Search Address"));
     |                     ^~~~~~~~~~~~~~~~~~
make[2]: *** [Source/Core/DolphinQt/CMakeFiles/dolphin-emu.dir/build.make:1476: Source/Core/DolphinQt/CMakeFiles/dolphin-emu.dir/Debugger/MemoryWidget.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:2256: Source/Core/DolphinQt/CMakeFiles/dolphin-emu.dir/all] Error 2
make: *** [Makefile:156: all] Error 2

I found this thread where someone said this error results from using an older version of Qt, but from the output of the dependency install command, it looks like I'm already using version 5.15:

Code:

qtbase5-dev is already the newest version (5.15.3+dfsg-2ubuntu0.2).
qtbase5-private-dev is already the newest version (5.15.3+dfsg-2ubuntu0.2).

I also found that "qmake -v" shows a version 5.9.7 Anaconda install:

Code:

QMake version 3.1
Using Qt version 5.9.7 in /home/griffin/anaconda3/lib

I'm not sure whether this is relevant or how to determine which version is being used.

I'd greatly appreciate any help with resolving this issue. Thank you!