make descriptions of each installable type an own subsection

this is easier to edit, provides anchors for free, and renders correctly
on the terminal without additional effort.
This commit is contained in:
Valentin Gagarin 2023-01-19 12:39:07 +01:00
parent 0507462c06
commit 1e87d5f1ea

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@ -50,9 +50,17 @@ manual](https://nixos.org/manual/nix/stable/).
Many `nix` subcommands operate on one or more *installables*. These are
command line arguments that represent something that can be built in
the Nix store. Here are the recognised types of installables:
the Nix store.
* **Flake output attributes**: `nixpkgs#hello`
For most commands, if no installable is specified, the default is `.`,
i.e. Nix will operate on the default flake output attribute of the
flake in the current directory.
Here are the recognised types of installables:
## Flake output attributes
Example: `nixpkgs#hello`
These have the form *flakeref*[`#`*attrpath*], where *flakeref* is a
flake reference and *attrpath* is an optional attribute path. For
@ -108,12 +116,16 @@ the Nix store. Here are the recognised types of installables:
attributes `packages.x86_64-linux.hello`,
`legacyPackages.x86_64-linux.hello` and `hello`.
* **Store paths**: `/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10`
## Store paths
Example: `/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10`
These are paths inside the Nix store, or symlinks that resolve to a
path in the Nix store.
* **Store derivations**: `/nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv`
## Store derivations
Example: `/nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv`
By default, if you pass a [store derivation] path to a `nix` subcommand, the command will operate on the [output path]s of the derivation.
@ -129,22 +141,22 @@ the Nix store. Here are the recognised types of installables:
If you want to operate on the store derivation itself, pass the
`--derivation` flag.
* **Nix attributes**: `--file /path/to/nixpkgs hello`
## Nix attributes
Example: `--file /path/to/nixpkgs hello`
When the `-f` / `--file` *path* option is given, installables are
interpreted as attribute paths referencing a value returned by
evaluating the Nix file *path*.
* **Nix expressions**: `--expr '(import <nixpkgs> {}).hello.overrideDerivation (prev: { name = "my-hello"; })'`.
## Nix expressions
Example: `--expr '(import <nixpkgs> {}).hello.overrideDerivation (prev: { name = "my-hello"; })'`.
When the `--expr` option is given, all installables are interpreted
as Nix expressions. You may need to specify `--impure` if the
expression references impure inputs (such as `<nixpkgs>`).
For most commands, if no installable is specified, the default is `.`,
i.e. Nix will operate on the default flake output attribute of the
flake in the current directory.
## Derivation output selection
Derivations can have multiple outputs, each corresponding to a