[Nix-dev] pathExists

[Nicolas Pierron]

On Sat, Feb 23, 2013 at 7:38 AM, Marco Maggesi <maggesi at math.unifi.it> wrote:
> Hello,
>
> I'm trying to create a pdf as follows
>
> let
>   pkgs = import <nixpkgs> {};
> in
> pkgs.texFunctions.runLaTeX {
>  rootFile = ./strengthened.tex;
> }
>
> And I get the following error:
>
> ...
> while evaluating the function at
> `/Users/maggesi/Devel/nixpkgs/pkgs/tools/typesetting/tex/nix/default.nix:68:40':
> while evaluating the builtin function `pathExists':
> string `/nix/store/6x6mcjdj07kwxnhwmcy62slih3pdvkv8-HOAT/article.cls'
> cannot refer to other paths
>
> What does it mean "cannot refer to other paths" in this case?
>
> Thanks?

My guess is that the input of pathExist is a string which is build
out-of a derivation path, so it is considered as being in the context
of the other derivation and thus it cannot be evaluated because this
would be an impurity in our Nix expression.

-- 
Nicolas Pierron
http://www.linkedin.com/in/nicolasbpierron - http://nbp.name/