From Makefile.in: ``` # * make check-stage1-rustdocck: Builds rustdoc. It has the advantage to compile # quite quickly since we're only using stage1 # executables. ``` However, this doesn't seem to work. Am I doing something wrong? ``` $ make check-stage1-rustdocck make: *** No rule to make target `check-stage1-rustdocck'. Stop. ``` The same also goes for `make check-stage1-std`.