[Nix-dev] new possible movement to git (?)

[Eelco Dolstra]

Hi,

On 08/24/2011 11:02 PM, Shea Levy wrote:

> It has been over a year since this discussion and I have not seen any
> move toward implementing the suggestions in the thread. If this is
> simply due to inertia, I would like to offer up help similar to what
> Marc Weber offers in his initial email (migrating scripts, providing
> advice to users, etc.). If it is because the NixOS community is
> undecided as to which vcs to switch to, perhaps we should have a
> discussion about how to fairly discuss and decide such things?

I've been meaning to set a Git migration into motion for a while, but I 
haven't really been able to find the time.  (Or the motivation, really - 
I don't seem to be suffering from Subversion to the same extent as other 
people...)

Anyway, to make a switch to a new DVCS more worthwhile, I'd like to use 
it as an opportunity to improve NixOS/Nixpkgs stability.  Right now 
doing an "svn up" is rather dangerous, since the trunk it quite often in 
a broken state.  Also, the binaries in the Nixpkgs channel lag behind 
the Subversion repository, so doing an upgrade may require building lots 
of packages from source.

So it would be nice if we had a more stable tree that users can update 
from safely.  For example, we could have these Nixpkgs/NixOS trees/branches:

- An "unstable" tree which receives developer commits.  It might be in a 
broken state, so end users shouldn't use it.  Hydra continuously builds 
it.  Of course, complicated changes should be done in a feature 
tree/branch and pulled in when they're done.

- A "tested" tree that automatically gets updated from the "unstable" 
tree when some set of Nixpkgs and NixOS tests succeed *and* the Nixpkgs 
channel is up to date.  This tree should be fairly safe to use.

- A "stable" tree that gets updated manually and conservatively (e.g., 
only security or stability updates).

Does this sound reasonable?

About where to host the repositories: we could do it on nixos.org, but 
using Github is rather nice because then I don't have to manage users or 
set up a web interface, and the pull request management seems rather nice.

Random point: should the NixOS and Nixpkgs trees be in the same 
repository?  I think so, since it allows them to be updated atomically, 
which is important given that Nixpkgs and NixOS changes are often related.

-- 
Eelco Dolstra | http://www.st.ewi.tudelft.nl/~dolstra/