This is primarily useful in Nix expressions that are also intended to
be used by nix-shell. It allows saying things like:
buildInputs = [ ... ] ++ (if inNixShell then [ emacs ] else [ ]);
This should not be used in Nixpkgs (since the question of what
constitutes a useful nix-shell environment is very subjective).
This makes it a bit easier to find out the current Nixpkgs version,
e.g.
$ nix-instantiate --eval '<nixpkgs>' -A lib.nixpkgsVersion
"14.02.35657.66f51a9"
It is parameterized by a function that takes a name and evaluates to the
option type for the attribute of that name. Together with
submoduleWithExtraArgs, this subsumes nixosSubmodule.
We cannot auto build amdadl-sdk on hydra, so setting license to unfree disable
auto builds. I also remove amdadl license, because it's irrelevant.
vcunat changed string license to attribute.
Nix-env always wants to install all outputs of a derivation, but this
failed for openjdk/openjre because openjdk has some symlinks (such as
bin/java) to openjre. Also, it prevents installing the openjre
without the openjdk. So as a workaround, mess with the "outputs"
attribute to fool nix-env.
Also, give openjre a separate name and description.
Fixes #1535.
E.g.
The unique option `fileSystems./.device' is defined multiple times, in `/etc/nixos/configuration.nix' and `/etc/nixos/foo.nix'.
This requires passing file/value tuples to the merge functions.
An annoying and dangerous property of "types.string" is that it merges
multiple definitions by concatenating them, which almost never
produces a sensible result. (Those options for which it does make
sense typically should use "types.lines" instead, and things only work
because the option definitions already end in a newline.) Of course,
you can use "types.uniq types.string", but that's rather verbose, and
inconsistent with other basic types like "types.int".
Changing the behaviour of "types.string" to be unique by default is
not an option, given the large number of options that use it. So
instead, we now have "types.str", which is equivalent to "types.uniq
types.string".
