[Nix-dev] Understanding NIX_PATH

[Luca Bruno]

If you knew the answer, that's the answer: "It's just there if someone
wants to use that path.", just there for convenience and historical
reasons. Nothing more.

On Sat, Jun 13, 2015 at 3:14 PM, Eike <eike at eknet.org> wrote:

>
> Yes, I know. My question is more why does it exist by default and is set
> to some non-existent path? I didn't tweak this variable myself. Does it
> maybe only apply to non-NixOS systems that use Nix?
>
> Thanks
> Eike
>
> Luca Bruno <lethalman88 at gmail.com> writes:
>
> > It's just there if someone wants to use that path.
> >
> > On Sat, Jun 13, 2015 at 1:58 PM, Eike <eike at eknet.org> wrote:
> >
> >>
> >> oh how embarrassing. I didn't see this although looking at it for sooo
> >> long.
> >>
> >> One thing I don't understand: what does 'nixpkgs=/etc/nixos/nixpkgs'
> >> mean in NIX_PATH? It doesn't exist on my system, so I gues it is
> >> referring to something…?
> >>
> >> thank you very much!
> >> Eike
> >>
> >> Luca Bruno <lethalman88 at gmail.com> writes:
> >>
> >> > I think because you are using the nixpkgs-unstable instead of
> >> > nixos-unstable, hence the NIX_PATH is wrong. Does /nix/var/nix/
> >> > profiles/per-user/root/channels/nixos/nixpkgs/nixos exist? If not,
> your
> >> > NIX_PATH is wrong.
> >> >
> >> > On Sat, Jun 13, 2015 at 12:54 PM, Eike <eike at eknet.org> wrote:
> >> >
> >> >>
> >> >> Hello all,
> >> >>
> >> >> I just encountered a problem that I cannot figure out myself. I
> switched
> >> >> from the 14.12 channel to the unstable channel (in NixOS) and when
> doing
> >> >> nixos-rebuild build I get the following:
> >> >>
> >> >>     # nix-channel --list
> >> >>     nixos https://nixos.org/channels/nixpkgs-unstable
> >> >>
> >> >>     # nixos-rebuild build
> >> >>     building Nix...
> >> >>     error: file ‘nixpkgs/nixos’ was not found in the Nix search path
> >> (add
> >> >> it using $NIX_PATH or -I)
> >> >>     error: file ‘nixpkgs/nixos’ was not found in the Nix search path
> >> (add
> >> >> it using $NIX_PATH or -I)
> >> >>     error: file ‘nixpkgs’ was not found in the Nix search path (add
> it
> >> >> using $NIX_PATH or -I)
> >> >>     /tmp/nixos-rebuild.lH7Hoj/nix
> >> >>     building the system configuration...
> >> >>     error: file ‘nixpkgs/nixos’ was not found in the Nix search path
> >> (add
> >> >> it using $NIX_PATH or -I)
> >> >>
> >> >> My nix env is this:
> >> >>
> >> >>     # env |grep -i ^nix
> >> >>     NIX_PROFILES=/run/current-system/sw /nix/var/nix/profiles/default
> >> >> /root/.nix-profile
> >> >>     NIX_CONF_DIR=/etc/nix
> >> >>
> >> >>
> >>
> NIX_PATH=/nix/var/nix/profiles/per-user/root/channels/nixos:nixpkgs=/etc/nixos/nixpkgs:nixos-config=/etc/nixos/configuration.nix
> >> >>     NIX_OTHER_STORES=/run/nix/remote-stores/*/nix
> >> >>     NIXPKGS_CONFIG=/etc/nix/nixpkgs-config.nix
> >> >>     NIX_USER_PROFILE_DIR=/nix/var/nix/profiles/per-user/root
> >> >>
> >> >> I can see that the 'nixpkgs=/etc/nixos/nixpkgs' part in NIX_PATH
> points
> >> >> to a non-existing thing. But it always did so and the command works
> in
> >> >> the same env if the 14.12 channel is active.
> >> >>
> >> >> I always wondered about why is nixpkgs pointing to a non-existing
> thing?
> >> >>
> >> >> And why is the unstable channel not building for me?
> >> >>
> >> >> Thank you and kind regards
> >> >> Eike
> >> >> _______________________________________________
> >> >> nix-dev mailing list
> >> >> nix-dev at lists.science.uu.nl
> >> >> http://lists.science.uu.nl/mailman/listinfo/nix-dev
> >> >>
> >>
> >> --
> >> gpg: AD7AC35E
> >> finger print: 137F BB0B 1639 D25F DC5D  E59C B412 C5F5 AD7A C35E
> >>
>
> --
> gpg: AD7AC35E
> finger print: 137F BB0B 1639 D25F DC5D  E59C B412 C5F5 AD7A C35E
>



-- 
NixOS Linux <http://nixos.org>
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