[snapshot-dir.py] Check if dest-dir is indeed a TriBITS installation

[nschloe]

We can probably improve the snapshotter a little bit. One of the things missing is a check if dest-dir is indeed a TriBITS installation, which makes it harder to shoot oneself in the foot.

I think I'll code around a little and file a pull request later.

[bartlettroscoe]

Nico,

The snapshot-dir.py script is actually a completely generic script for snapshotting from one git repo to another Therefore, it does not make sense to put in TriBITS-specific logic in that scripts. Also, it will break the usage of the script for snapshoting other repos and dirs.

However, in the not-to-distant future, TriBITS will be reorganized (I am writing a new Story Issue for that now to give an idea) and will provide a TriBITS-specific snapshot-tribits.py tool that will allow for targeted snapshotting of only the parts of TriBITS that are desired. I would be used like:

$ cd <some-project>/cmake/tribits/
$ .<some-base-dir>/TriBITS/tribits/snapshot-tribits.py --core

That would only snapshot the minimal part of TriBITS that is needed for the package-based architecture which has no dependencies on anything but CMake 2.8.11 and nothing else.

Since Trilinos uses all of TriBITS, it would use:

$ cd Trilinos/cmake/tribits/
$ ../..//TriBITS/tribits/snapshot-tribits.py --all

Other projects could pick and choose what they wanted to snapshot and use.

I will provide more detail in the new Story Issue that I am writing.