[PATCH] build: allow some python variable overrides

[Gustavo Zacarias]

On 02/04/2014 01:39 PM, Paul Kölle wrote:
> Hi Zacarias,
> 
> Ah, so "" ->(empty string) is a valid override from os_env? The
> canonical fix would be to test for identity not equality (is not None):

Thanks Paul, spun a V2 patch and sent.
Regards.