* manual: Contributing -> Development, Hacking -> Building what's currently called "hacking" are really instructions for setting up a development environment and compiling from source. we have a contribution guide in the repo (which rightly focuses on GitHub workflows), and the material in the manual is more about working on the code itself. since we'd otherwise have three headings that amount to "Building Nix", this change also moves the "classic Nix" instructions to the top. we may want to reorganise this in the future, and bring contributor-oriented information closer to the code, but for now let's stick to more accurate names to ease navigation.
3.3 KiB
Name
nix-store --realise
- build or fetch store objects
Synopsis
nix-store
{--realise
| -r
} paths… [--dry-run
]
Description
Each of paths is processed as follows:
- If the path leads to a store derivation:
- If it is not valid, substitute the store derivation file itself.
- Realise its output paths:
- Try to fetch from substituters the store objects associated with the output paths in the store derivation's closure.
- With content-addressed derivations (experimental): Determine the output paths to realise by querying content-addressed realisation entries in the Nix database.
- For any store paths that cannot be substituted, produce the required store objects:
- Realise all outputs of the derivation's dependencies
- Run the derivation's
builder
executable
- Otherwise, and if the path is not already valid: Try to fetch the associated store objects in the path's closure from substituters.
If no substitutes are available and no store derivation is given, realisation fails.
The resulting paths are printed on standard output. For non-derivation arguments, the argument itself is printed.
{{#include ../status-build-failure.md}}
Options
-
--dry-run
Print on standard error a description of what packages would be built or downloaded, without actually performing the operation.
-
--ignore-unknown
If a non-derivation path does not have a substitute, then silently ignore it.
-
--check
This option allows you to check whether a derivation is deterministic. It rebuilds the specified derivation and checks whether the result is bitwise-identical with the existing outputs, printing an error if that’s not the case. The outputs of the specified derivation must already exist. When used with
-K
, if an output path is not identical to the corresponding output from the previous build, the new output path is left in/nix/store/name.check.
{{#include ./opt-common.md}}
{{#include ../opt-common.md}}
{{#include ../env-common.md}}
Examples
This operation is typically used to build store derivations produced by
nix-instantiate
:
$ nix-store --realise $(nix-instantiate ./test.nix)
/nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1
This is essentially what nix-build
does.
To test whether a previously-built derivation is deterministic:
$ nix-build '<nixpkgs>' --attr hello --check -K
Use nix-store --read-log
to show the stderr and stdout of a build:
$ nix-store --read-log $(nix-instantiate ./test.nix)