The previous coding worked as long as MODULEDIR wasn't set explicitly,
because we create sharedir/$(datamoduledir) and the default value of
that is "extension". But if some other value is specified for MODULEDIR
then the installation directory needed for the control file wasn't made.
CΓ©dric Villemain
installdirs:
+ifneq (,$(EXTENSION))
+ $(MKDIR_P) '$(DESTDIR)$(datadir)/extension'
+endif
ifneq (,$(DATA)$(DATA_built))
$(MKDIR_P) '$(DESTDIR)$(datadir)/$(datamoduledir)'
endif