> > Martin, can you please elaborate on this? I never heard of such
> > "standards" in OSS.
> 
> MAL already gave the link. From the link:
> 
> Sometimes package developers are tempted to set user variables such as
> CFLAGS because it appears to make their job easier. However, the package
> itself should never set a user variable, particularly not to include
> switches that are required for proper compilation of the package. Since
> these variables are documented as being for the package builder, that
> person rightfully expects to be able to override any of these variables
> at build time.

So one day package builder by right will set CFLAGS to make their job
easier and python build system will not ignore it.