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.