+# Can't use GNU tar's --transform, needs to build under Alpine Linux
+advent-$(VERS).tar.gz: $(SOURCES) $(DOCS)
+ @ls $(SOURCES) $(DOCS) | sed s:^:advent-$(VERS)/: >MANIFEST
+ @(ln -s . advent-$(VERS))
+ (tar -T MANIFEST -czvf advent-$(VERS).tar.gz)
+ @(rm advent-$(VERS))