Directly register the store classes rather than a function to build an
instance of them.
This gives the possibility to introspect static members of the class or
choose different ways of instantiating them.
I think this better captures the intent of what's going on: we either
have an opaque store path, or a drv path with some outputs.
Having this structure will also help us support CA derivations: we'll
have to allow the outpath paths to be optional, so the structure we gain
now makes up for the structure we loose then.
'nix run' will try to run $out/bin/<name>, where <name> is the
derivation name (excluding the version). This often works well:
$ nix run nixpkgs#hello
Hello, world!
$ nix run nix -- --version
nix (Nix) 2.4pre20200626_adf2fbb
$ nix run patchelf -- --version
patchelf 0.11.20200623.e61654b
$ nix run nixpkgs#firefox -- --version
Mozilla Firefox 77.0.1
$ nix run nixpkgs#gimp -- --version
GNU Image Manipulation Program version 2.10.14
though not always:
$ nix run nixpkgs#git
error: unable to execute '/nix/store/kp7wp760l4gryq9s36x481b2x4rfklcy-git-2.25.4/bin/git-minimal': No such file or directory
The initial contents of the flake is specified by the
'templates.<name>' or 'defaultTemplate' output of another flake. E.g.
outputs = { self }: {
templates = {
nixos-container = {
path = ./nixos-container;
description = "An example of a NixOS container";
};
};
};
allows
$ nix flake init -t templates#nixos-container
Also add a command 'nix flake new', which is identical to 'nix flake
init' except that it initializes a specified directory rather than the
current directory.
InstallableValue has children InstallableFlake and InstallableAttrPath, but InstallableFlake was overriding toDerivations, and usage was changed so that InstallableFlake didn't need cmd. So these changes were made:
InstallableValue::toDerivations() -> InstalllableAttrPath::toDerivations()
InstallableValue::cmd -> InstallableAttrPath::cmd
InstallableValue uses state instead of cmd
toBuildables() and toDerivations() were made abstract
That is, unless --file is specified, the Nix search path is
synthesized into an attribute set. Thus you can say
$ nix build nixpkgs.hello
assuming $NIX_PATH contains an entry of the form "nixpkgs=...". This
is more verbose than
$ nix build hello
but is less ambiguous.
