Comment 7 for bug 1188627

I think it does something like the following...

1. make dist (i.e., generate the tarball)
2. extract the distributed package
3. configure and make
4. make check (i.e., run any available automated tests)
5. Install into a temp folder
6. Run a few sanity checks on any binary targets... e.g., it checks that "inkscape --help" and "inkscape --version" etc give sensible replies.
7. Uninstalls from temp folder and checks that no crap is left behind
8. make dist (using the temp package)

I'm sure it has a few other useful tricks up its sleeve too!