-developer-build broken with disabled features due to the -Werror and unused variables/parameters

~/Development/qt5/qtbase/configure -prefix ~/Development/qt5.9_git -developer-build -opensource -confirm-license -no-pch -skip qtwebkit -skip qtwebkit-examples -skip qt3d -skip qtxmlpatterns -skip qtwayland -skip qtwebengine -skip qtwebview -skip qtmultimedia -skip qtlocation -skip qtcanvas3d -skip qtwebsockets -skip qtwebchannel -skip qtenginio -skip qtsensors -skip qtserialport -skip qtpurchasing -skip qtquick1 -skip qtscript -skip qtconnectivity -skip qtcharts -skip qtdatavis3d -skip qtgamepad -skip qtvirtualkeyboard -skip qtscxml -skip qtremoteobjects -skip qtspeech -skip qtnetworkauth -no-feature-bearermanagement -no-feature-colordialog -no-feature-columnview -no-feature-commandlinkbutton -no-feature-cssparser -no-feature-cups -no-feature-datawidgetmapper -no-feature-dial -no-feature-dockwidget -no-feature-fontdialog -no-feature-ftp -no-feature-imageformat_bmp -no-feature-itemviews -no-feature-lcdnumber -no-feature-listview -no-feature-listwidget -no-feature-mdiarea -no-feature-mimetype -no-feature-movie -no-feature-pdf -no-feature-printdialog -no-feature-printer -no-feature-printpreviewdialog -no-feature-printpreviewwidget -no-feature-qml-network -no-feature-quick-designer -no-feature-quick-flipable -no-feature-quickcontrols2-universal -no-feature-tableview -no-feature-tablewidget -no-feature-textodfwriter -no-feature-treeview -no-feature-treewidget -no-feature-undocommand -no-feature-undogroup -no-feature-undostack -no-feature-undoview -no-feature-wizard -no-feature-xmlstreamwriter -nomake examples -nomake tests