Development model

[leezu]

While I agree that squashing all commits to avoid a huge .git folder makes sense to speed up cloning of mxnet, I believe you should not delete old commits from dmlc/cub as it breaks checking out older versions of mxnet that relied on those.

Checking out old versions of mxnet can be important when debugging changes introduced between two revisions (git bisect). Another usecase is when having some code that was not touched for a while and used to work but does not work with current mxnet master ;)

@mli, what do you think? Of course you can't change this retrospectively, but perhaps you agree that it makes sense not to change the history of this repo in the future?

[leezu]

Ok, I realized the old history is still present upstream (https://github.com/NVlabs/cub/).

That makes it possible to fix the history mess:

• Add a branch upstream to https://github.com/dmlc/cub containing all of the history (note this will blow up the .git folder again)
• Create a new repository https://github.com/dmlc/cub-new only containing the squashed commits
• Change mxnet master to track cub-new from now on.

Thereby checking out old revisions of mxnet will work without problems, as they will refer to https://github.com/dmlc/cub that contains all commits. Checkouts of the master will benefit from the speedup in https://github.com/dmlc/cub-new .