[Nix-dev] Re: Removing nulls in BuildInputs

[Lluís Batlle i Rossell]

On Sun, Oct 24, 2010 at 12:56:58PM +0200, Ludovic Courtès wrote:
> Hello,
> 
> roconnor at theorem.ca writes:
> 
> > There was an idea tossed around on #nixos a few days ago that
> > mkDerivation should remove the nulls from buildInputs (and maybe other
> > items too). This would help make more consistent hashes that now
> > currently change when we do refactoring that removes an item from the
> > build input vs setting it to null.
> 
> Yes, but OTOH, I think it’s a sign of sloppiness when you end up with
> nulls in ‘buildInputs’.
> 
> IOW, the ‘buildInputs’ list should be built up carefully so that it
> contains exactly what’s needed.

I remember having the stdenv adapter for cross building supposing that there are
not nulls, and it took me a while to realize about the source of the problem
until I found that there were nulls in buildInputs. I had written all without
having in mind that sometimes there were nulls in buildInputs.