[Nix-dev] Checker for unknown attributes in configuration.nix .

[Michael Raskin]

	Hello.
I've just checked in a complex commit that includes 'configuration.nix
checker'. I think it deserves announcement. It allows you (look at
system.nix for details) to assert that all options mentioned in
configuration.nix do correspond to options in options.nix .
	That means that if someone renames an option (OK, failed to mention -
without creating a completely different one with the old name) your
build fails, you have an error in system.nix and you even get the name
of the now redundant option. Think of typos also - usually, having
mistyped options is hard to find, but as they are not in options.nix...

Now my questions:
1) What improvements should be done?
2) Should it be on by default? Note that it being on can ruin a build
during upgrade, so is the bonus worth it?

Thanks, goodbye
	Michael Raskin