term progressbox = `VBox(
            `HSpacing(40),
            // popup heading
            `Heading (heading),
            `Left (`HBox (
                `VBox (
                    `Left (`Label (`opt (`boldFont), _("Package: "))),
                    `Left (`Label (`opt (`boldFont), _("Size: ")))
                ),
                `VBox (
                    `Left (`Label (name)),
                    `Left (`Label (sz))
                )
            )),
            `ProgressBar(`id(`progress), "", 100, 0 ),
            `HBox (
                `HStretch (),
                `PushButton (`id (`abort), Label::AbortButton ()),
                `HStretch ()
            )
        );

Is not displayed correctly. I'd expect that "Package: " and "Size: " are left-alligned with each other and the same for the values, but both of them are center-alligned.