[Nix-dev] Re: Libre Software Meeting talk about NixOS

[Jeff Johnson]

On Jul 10, 2010, at 10:01 AM, Ludovic Courtès wrote:

> Hello,
> 
>> 
>> Yeah, as if any existing distro ever managed to introduce any significant 
>> changes.
> 

(aside)
Yes that _IS_ a huge problem with distros and packaging. It's
way too easy to argue that the cost of changing anything far
outweighs benefits of innovation.

> Well, there’s Mancoosi, a European project which, among other things,
> intends to retrofit transactional upgrades and rollback in an existing
> distro (Debian IIRC):
> 
>  http://www.mancoosi.org/
> 
> I’m skeptical about the feasibility of such a thing, though.
> 

Not to honk my own warez or anything, but RPM has had --rollback
for most of this century and --rollback has been deployed in
a "production" CGL for many years now. WORKSFORME.

If you ever receive a SMS from Brazil, you've likely traversed the RPM
software. And the CGL with --rollback is deployed in far more countries
than Brazil. More than that I cannot say because of a NDA muzzle.

But I'd like to hear the details of your --rollback skepticism no matter what.

I personally am conflicted about whether --rollback is useful for software
distribution.

The killer design issue is scripting with --rollback. Its extremely
hard to permit general scripting side-effects whose effects can ALWAYS
be reversed by --rollback.

> And then there are other Nix/NixOS features that would still be lacking,
> such as the power of purely functional builds and deployments that we’ve
> got used to.
> 

Which is largely why I'm here shopping a better mousetrap with NixOS
that has some chance of eliminating ALL scripting side-effects in
a "functional packaging" paradigm.

73 de Jeff