This is the intended directory structure for several versions of the tutorial on the server:

$ tree -L 2 $(TUTORIAL_DIR) $(TUTORIAL_DIR) ├── 1.0 │   ├── files │ │   ├── tutorial │ │   └── tutorial.tar.gz │   └── src ├── 2.0 │   ├── files │ │   ├── tutorial │ │   └── tutorial.tar.gz │   └── src ├── dev │   ├── files -> /var/www/data/git/tutorial/files │   └── src -> /var/www/data/git/tutorial/src └── stable -> 2.0

The Makefile helps to maintain a directory of versions of the tutorial like

$ make show-help $ TUTORIAL_VERSION=x.y make install set-stable

Do not forget to add a new version to Site_doc.tutorial_version.