[Nix-dev] Re: "live builds" proposal

[Yury G. Kudryashov]

Eelco Dolstra wrote:

> Hi,
> 
> On 08/01/2010 01:20 AM, Yury G. Kudryashov wrote:
> 
>> I propose the following extension to the nix language that will allow
>> native support for "live scm builds" etc.
>> 
>> If nix is called with --enable-exec, the new function builtins.exec is
>> added. The proposed syntax is like the following:
> 
> This is already kind of possible (if I understand correctly what you
> want).  For instance, to obtain the current head revision of a SVN
> repository:
> 
> rev = import (pkgs.runCommand "head-revision.nix"
I want to run a command while evaluating the expression, not instantiating 
it. The command should be run as evaluating user, and create some 
directory/file in user's home directory. Then "pure" nix language can import 
the result of this command.