Pin nixpkgs version
Add option to build "world" set from pinned nixpkgs version in addition
to option to build is as overlay. Pinned nixpkgs version is know to
work, and, by definition of pin, will not break. Building "world" may
break due upgrade of "nixpkgs" channel, but enables use of latests and
greatest versions of dependencies.
Another minor inconvenience is that build with pinned nixpkgs:
$ nix-build -A world
$ nix-env -i ./result
ignores meta.priority, which may lead to more file conflicts.
Drop unsuccesfull attempts to deploy config with Nix
Write Nix derivation to deploy config files
Now, in addition to `config.tar.gz', configuration files
could be deployed in Nix-style.
With this approach, configuration files are stored read-only in profile
(~/.nix-profile/share/config.tgz) and configuration files at expected
locations (~/.vimrc, for example) becomes symbolic link to corresponding
file in profile.
This way, if configuration file is ever removed, corresponding symbolic
link becomes dangling and easy to locate. This property is not provided
by `config.tar.gz' approach.
Add receipt to build config.tar.gz with Nix