Deja-dup 34.3 fails to build with vala 0.35.6

Vala 0.35.x (0.36 to be) fails to translate deja-dup:

[ 9%] Generating ConfigBool.c, ConfigChoice.c, ConfigDelete.c, ConfigEntry.c, ConfigFolder.c, ConfigLabel.c, ConfigLabelBackupDate.c, ConfigLabelDescription.c, ConfigLabelLocation.c, ConfigList.c, ConfigLocation.c, ConfigLocationCustom.c, ConfigLocationDAV.c, ConfigLocationFile.c, ConfigLocationFTP.c, ConfigLocationGCS.c, ConfigLocationGDrive.c, ConfigLocationOpenstack.c, ConfigLocationRackspace.c, ConfigLocationS3.c, ConfigLocationSSH.c, ConfigLocationSMB.c, ConfigLocationTable.c, ConfigLocationU1.c, ConfigLocationVolume.c, ConfigPeriod.c, ConfigRelPath.c, ConfigURLPart.c, ConfigURLPartBool.c, ConfigWidget.c, WidgetUtils.c, widgets.vapi, widgets.h, widgets_internal.h
/home/abuild/rpmbuild/BUILD/deja-dup-34.3/deja-dup/widgets/ConfigList.vala:336.39-336.42: error: Argument 1: Cannot pass value to reference or output parameter
      (model as Gtk.ListStore).remove(iter);
                                      ^^^^
/home/abuild/rpmbuild/BUILD/deja-dup-34.3/deja-dup/widgets/ConfigLocation.vala:400.18-400.21: error: Argument 1: Cannot pass value to reference or output parameter
    store.remove(iter);
                 ^^^^
/home/abuild/rpmbuild/BUILD/deja-dup-34.3/deja-dup/widgets/ConfigLocation.vala:405.22-405.29: error: Argument 1: Cannot pass value to reference or output parameter
        store.remove(sep_iter);
                     ^^^^^^^^

** (valac:12386): CRITICAL **: vala_data_type_get_nullable: assertion 'self != NULL' failed

(valac:12386): GLib-GObject-WARNING **: invalid cast from 'ValaNamespace' to 'ValaTypeSymbol'

(valac:12386): GLib-GObject-WARNING **: invalid cast from 'ValaNamespace' to 'ValaTypeSymbol'

(valac:12386): GLib-GObject-WARNING **: invalid cast from 'ValaNamespace' to 'ValaTypeSymbol'

(valac:12386): GLib-GObject-WARNING **: invalid cast from 'ValaNamespace' to 'ValaTypeSymbol'
Compilation failed: 3 error(s), 0 warning(s)