forked from lix-project/lix
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
parent
0507462c06
commit
1e87d5f1ea
192
src/nix/nix.md
192
src/nix/nix.md
|
|
@ -50,101 +50,113 @@ 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:
|
||||
|
||||
* **Flake output attributes**: `nixpkgs#hello`
|
||||
|
||||
These have the form *flakeref*[`#`*attrpath*], where *flakeref* is a
|
||||
flake reference and *attrpath* is an optional attribute path. For
|
||||
more information on flakes, see [the `nix flake` manual
|
||||
page](./nix3-flake.md). Flake references are most commonly a flake
|
||||
identifier in the flake registry (e.g. `nixpkgs`), or a raw path
|
||||
(e.g. `/path/to/my-flake` or `.` or `../foo`), or a full URL
|
||||
(e.g. `github:nixos/nixpkgs` or `path:.`)
|
||||
|
||||
When the flake reference is a raw path (a path without any URL
|
||||
scheme), it is interpreted as a `path:` or `git+file:` url in the following
|
||||
way:
|
||||
|
||||
- If the path is within a Git repository, then the url will be of the form
|
||||
`git+file://[GIT_REPO_ROOT]?dir=[RELATIVE_FLAKE_DIR_PATH]`
|
||||
where `GIT_REPO_ROOT` is the path to the root of the git repository,
|
||||
and `RELATIVE_FLAKE_DIR_PATH` is the path (relative to the directory
|
||||
root) of the closest parent of the given path that contains a `flake.nix` within
|
||||
the git repository.
|
||||
If no such directory exists, then Nix will error-out.
|
||||
|
||||
Note that the search will only include files indexed by git. In particular, files
|
||||
which are matched by `.gitignore` or have never been `git add`-ed will not be
|
||||
available in the flake. If this is undesirable, specify `path:<directory>` explicitly;
|
||||
|
||||
For example, if `/foo/bar` is a git repository with the following structure:
|
||||
```
|
||||
.
|
||||
└── baz
|
||||
├── blah
|
||||
│ └── file.txt
|
||||
└── flake.nix
|
||||
```
|
||||
|
||||
Then `/foo/bar/baz/blah` will resolve to `git+file:///foo/bar?dir=baz`
|
||||
|
||||
- If the supplied path is not a git repository, then the url will have the form
|
||||
`path:FLAKE_DIR_PATH` where `FLAKE_DIR_PATH` is the closest parent
|
||||
of the supplied path that contains a `flake.nix` file (within the same file-system).
|
||||
If no such directory exists, then Nix will error-out.
|
||||
|
||||
For example, if `/foo/bar/flake.nix` exists, then `/foo/bar/baz/` will resolve to
|
||||
`path:/foo/bar`
|
||||
|
||||
If *attrpath* is omitted, Nix tries some default values; for most
|
||||
subcommands, the default is `packages.`*system*`.default`
|
||||
(e.g. `packages.x86_64-linux.default`), but some subcommands have
|
||||
other defaults. If *attrpath* *is* specified, *attrpath* is
|
||||
interpreted as relative to one or more prefixes; for most
|
||||
subcommands, these are `packages.`*system*,
|
||||
`legacyPackages.*system*` and the empty prefix. Thus, on
|
||||
`x86_64-linux` `nix build nixpkgs#hello` will try to build the
|
||||
attributes `packages.x86_64-linux.hello`,
|
||||
`legacyPackages.x86_64-linux.hello` and `hello`.
|
||||
|
||||
* **Store paths**: `/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`
|
||||
|
||||
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.
|
||||
|
||||
[output path]: ../../glossary.md#gloss-output-path
|
||||
|
||||
For example, `nix path-info` prints information about the output paths:
|
||||
|
||||
```console
|
||||
# nix path-info --json /nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv
|
||||
[{"path":"/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10",…}]
|
||||
```
|
||||
|
||||
If you want to operate on the store derivation itself, pass the
|
||||
`--derivation` flag.
|
||||
|
||||
* **Nix attributes**: `--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"; })'`.
|
||||
|
||||
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>`).
|
||||
the Nix store.
|
||||
|
||||
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
|
||||
more information on flakes, see [the `nix flake` manual
|
||||
page](./nix3-flake.md). Flake references are most commonly a flake
|
||||
identifier in the flake registry (e.g. `nixpkgs`), or a raw path
|
||||
(e.g. `/path/to/my-flake` or `.` or `../foo`), or a full URL
|
||||
(e.g. `github:nixos/nixpkgs` or `path:.`)
|
||||
|
||||
When the flake reference is a raw path (a path without any URL
|
||||
scheme), it is interpreted as a `path:` or `git+file:` url in the following
|
||||
way:
|
||||
|
||||
- If the path is within a Git repository, then the url will be of the form
|
||||
`git+file://[GIT_REPO_ROOT]?dir=[RELATIVE_FLAKE_DIR_PATH]`
|
||||
where `GIT_REPO_ROOT` is the path to the root of the git repository,
|
||||
and `RELATIVE_FLAKE_DIR_PATH` is the path (relative to the directory
|
||||
root) of the closest parent of the given path that contains a `flake.nix` within
|
||||
the git repository.
|
||||
If no such directory exists, then Nix will error-out.
|
||||
|
||||
Note that the search will only include files indexed by git. In particular, files
|
||||
which are matched by `.gitignore` or have never been `git add`-ed will not be
|
||||
available in the flake. If this is undesirable, specify `path:<directory>` explicitly;
|
||||
|
||||
For example, if `/foo/bar` is a git repository with the following structure:
|
||||
```
|
||||
.
|
||||
└── baz
|
||||
├── blah
|
||||
│ └── file.txt
|
||||
└── flake.nix
|
||||
```
|
||||
|
||||
Then `/foo/bar/baz/blah` will resolve to `git+file:///foo/bar?dir=baz`
|
||||
|
||||
- If the supplied path is not a git repository, then the url will have the form
|
||||
`path:FLAKE_DIR_PATH` where `FLAKE_DIR_PATH` is the closest parent
|
||||
of the supplied path that contains a `flake.nix` file (within the same file-system).
|
||||
If no such directory exists, then Nix will error-out.
|
||||
|
||||
For example, if `/foo/bar/flake.nix` exists, then `/foo/bar/baz/` will resolve to
|
||||
`path:/foo/bar`
|
||||
|
||||
If *attrpath* is omitted, Nix tries some default values; for most
|
||||
subcommands, the default is `packages.`*system*`.default`
|
||||
(e.g. `packages.x86_64-linux.default`), but some subcommands have
|
||||
other defaults. If *attrpath* *is* specified, *attrpath* is
|
||||
interpreted as relative to one or more prefixes; for most
|
||||
subcommands, these are `packages.`*system*,
|
||||
`legacyPackages.*system*` and the empty prefix. Thus, on
|
||||
`x86_64-linux` `nix build nixpkgs#hello` will try to build the
|
||||
attributes `packages.x86_64-linux.hello`,
|
||||
`legacyPackages.x86_64-linux.hello` and `hello`.
|
||||
|
||||
## 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
|
||||
|
||||
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.
|
||||
|
||||
[output path]: ../../glossary.md#gloss-output-path
|
||||
|
||||
For example, `nix path-info` prints information about the output paths:
|
||||
|
||||
```console
|
||||
# nix path-info --json /nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv
|
||||
[{"path":"/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10",…}]
|
||||
```
|
||||
|
||||
If you want to operate on the store derivation itself, pass the
|
||||
`--derivation` flag.
|
||||
|
||||
## 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
|
||||
|
||||
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>`).
|
||||
|
||||
## Derivation output selection
|
||||
|
||||
Derivations can have multiple outputs, each corresponding to a
|
||||
|
|
|
|||
Loading…
Reference in a new issue