qt GUI build failure

[BeyondAbstractions]

tried to build the project from src using cmake Qt-5.11.3 on Linux platform(Ubuntu-20.04).
also the CMakeLists.txt for GUI build contains hard-coded CMAKE_INSTALL_PREFIX which is bad:

elfparser/CMakeLists.txt

Line 81 in 39d21ca

set(CMAKE_PREFIX_PATH "~/Qt/5.2.0/gcc_64")

[ 82%] Building CXX object CMakeFiles/elfparser.dir/src/ui/inttablewidget.cpp.o [ 85%] Building CXX object CMakeFiles/elfparser.dir/lib/hash-lib/sha1.cpp.o [ 88%] Building CXX object CMakeFiles/elfparser.dir/lib/hash-lib/sha256.cpp.o [ 91%] Building CXX object CMakeFiles/elfparser.dir/lib/hash-lib/md5.cpp.o [ 94%] Building CXX object CMakeFiles/elfparser.dir/src/ui/mainwindow.cpp.o /home/akash/Programming/vscode_c_cpp_project_templates/cpp_libraries/elfparser/src/ui/mainwindow.cpp: In constructor ‘MainWindow::MainWindow(QWidget*)’: /home/akash/Programming/vscode_c_cpp_project_templates/cpp_libraries/elfparser/src/ui/mainwindow.cpp:32:52: error: invalid use of incomplete type ‘class QAction’ 32 | m_copyAction.reset(new QAction(tr("Copy"), this));