[Nix-dev] Updating emacs-snapshot package

[Phil Hagelberg]

ludo at gnu.org (Ludovic Courtès) writes:

> (Did you mean to reply to the list?)

Oops; I didn't notice it's one of _those_ kinds of lists. =)

>> Looks great! Is this kept out of the nixpkgs-unstable channel simply
>> because it's packaging software that hasn't seen a stable release?
>
> It’s not Nixpkgs, it’s Emacs.  :-)  So it has its own channel, at
> <http://hydra.nixos.org/jobset/gnu/emacs-trunk/channel/latest/MANIFEST>.
> But you can’t really use it easily.

I don't understand the distinction. Is keeping it in its own channel
comparable to the way PPAs (Personal Package Archives) work in Ubuntu?

>> I tried installing the closure with nix-store --import and it appeared
>> to place the files into /nix, but nothing emacs-related was added to my
>> path or placed in my profile. I'm sure I'm missing something obvious,
>> but it's not covered by the section on closures in the manual. 
>
> Normally something like this should work:
>
>   $ curl http://hydra.nixos.org/build/1822960/nix/closure/emacs-24.0.92.closure.gz | \
>       gunzip | sudo nix-store --import
>   $ nix-env -i /nix/store/a8s8p6353sr0waq6290r4kbiljfjk3gx-emacs-24.0.92
>
> This is what appears under “help” for “Nix closure” at
> <http://hydra.nixos.org/build/1822960>, with the addition of ‘sudo’ when
> running ‘nix-import’.

OK, great; thanks. I was just looking through the manual. I see now that
it's mentioned in the manual, but it's not very clear:

> Then if you do any Nix operation, e.g.
> $ nix-env -i firefox
> and Nix has to build a path that it sees is already present in
> /mnt/nix, then it will just copy from there instead of building it
> from source.

I think this wording could be made stronger. It sounds like an optional
step, but in most cases importing the closure has no effect without
this, right? Anyway, when I do "nix-env -i emacs" as per the manual, it
pulls in Emacs 23 from the network rather than using the closure I
imported, so it's not quite right anyway.

-Phil