[Nix-dev] Error evaluating nixpkgs

[Lluís Batlle i Rossell]

On Thu, Jul 29, 2010 at 12:24:58PM +0200, maggesi at math.unifi.it wrote:
> Hi,
> 
> since many days now I get the following error while trying to update
> my system:
> 
> # nix-env -u \* --show-trace
> error: while evaluating the function at
> `/etc/nixos/nixpkgs/pkgs/lib/customisation.nix:52:24':
> while evaluating the function at
> `/etc/nixos/nixpkgs/pkgs/applications/misc/ikiwiki/default.nix:1:1':
> value is an attribute set while a Boolean was expected
> 
> 
> I try from time to time to run nixos-checkout but the error remains.
> 
> It is only me?  Do I have something corrupted on my computer?  (I
> tried to checkout the svn repository for nixos and nixpkgs from
> scratch but nothing changes).

Not only you.
It's the getPkgConfig function, that until now gave trouble to many of us.

It looks for, in the config, the attributes [ "ikiwiki" "git" ] and expects a
boolean. If that does not exist, it looks for [ "git" ] and expects a boolean.
If you have a "git" attribute in your nixpkgs config, and it is not a boolean,
the evaluation will fail.

I don't like that fallback of getPkgConfig into using the 2nd attribute as a
main attribute of the config in case the 1st isn't there. I'd take it out and go
only with getConfig, but I don't know if anyone depends on it.