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

[Ludovic Courtès]

Hi Jeff,

Jeff Johnson <n3npq at mac.com> writes:

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

>> 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.

[...]

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

[...]

> 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.

You’ve already partly answered.  :-)

Are you saying that RPM-based distros already allow ‘--rollback’?  Or
that the RPM package manager has a ‘--rollback’ option that happens to
work *if* packages are side-effect-free, etc.?  Are upgrades atomic?

Thanks,
Ludo’.