| PROJECT_SOURCE_DIR | |
| ------------------ | |
| This is the source directory of the last call to the | |
| :command:`project` command made in the current directory scope or one | |
| of its parents. Note, it is not affected by calls to | |
| :command:`project` made within a child directory scope (i.e. from | |
| within a call to :command:`add_subdirectory` from the current scope). |