I recently unchecked 'translatable' for the currentText property of a combobox in the ui designer.
Someone else noted that Qt 4.8.6 for Ubuntu decided to to create a ui_ file that has setCurrentText, which is not in Qt4;
therefore, it fails to build.

Is this a Qt problem, Ubuntu package issue or am I missing something?

The only solution I can think of is to manually remove the currentText property from the .ui file.

https://github.com/LibreCAD/LibreCAD/issues/697