From 1bc9257d7c5980fb048b519eeaa2a2b2e8925099 Mon Sep 17 00:00:00 2001 From: Valentin Gagarin Date: Wed, 3 May 2023 15:36:13 +0200 Subject: [PATCH] reword description of how realisation works --- .../src/command-ref/nix-store/opt-common.md | 4 +- .../src/command-ref/nix-store/realise.md | 50 +++++++++---------- 2 files changed, 27 insertions(+), 27 deletions(-) diff --git a/doc/manual/src/command-ref/nix-store/opt-common.md b/doc/manual/src/command-ref/nix-store/opt-common.md index dd9a6bf21..104b20076 100644 --- a/doc/manual/src/command-ref/nix-store/opt-common.md +++ b/doc/manual/src/command-ref/nix-store/opt-common.md @@ -1,6 +1,6 @@ -# Options +# Command options -The following options are allowed for all `nix-store` operations, but may not always have an effect. +The following options are allowed for all operations in the `nix-store` command, but may not always have an effect. - [`--add-root`](#opt-add-root) *path* diff --git a/doc/manual/src/command-ref/nix-store/realise.md b/doc/manual/src/command-ref/nix-store/realise.md index c19aea75e..2881a69b3 100644 --- a/doc/manual/src/command-ref/nix-store/realise.md +++ b/doc/manual/src/command-ref/nix-store/realise.md @@ -8,33 +8,37 @@ # Description -The operation `--realise` essentially “builds” the specified store -paths. Realisation is a somewhat overloaded term: +Ensure that the given [store paths] are [valid]. - - If the store path is a *derivation*, realisation ensures that the - output paths of the derivation are [valid] (i.e., - the output path and its closure exist in the file system). This - can be done in several ways. First, it is possible that the - outputs are already valid, in which case we are done - immediately. Otherwise, there may be [substitutes] - that produce the outputs (e.g., by downloading them). Finally, the - outputs can be produced by running the build task described - by the derivation. +Realisation of a store path works as follows: - - If the store path is not a derivation, realisation ensures that the - specified path is valid (i.e., it and its closure exist in the file - system). If the path is already valid, we are done immediately. - Otherwise, the path and any missing paths in its closure may be - produced through substitutes. If there are no (successful) - substitutes, realisation fails. +- If the path is already valid, do nothing. +- If the path leads to a [store derivation]: + 1. Realise the store derivation file itself, as a regular store path. + 2. 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 build certificates in the [Nix database]. + - For any store paths that cannot be substituted, produce the required store objects by first realising all outputs of the derivation's dependencies and then running the derivation's build instructions. +- Otherwise: Try to fetch the associated [store objects] in the paths' [closure] from the [substituters]. +If no substitutes are available and no store derivation is given, realisation fails. + +[store paths]: @docroot@/glossary.md#gloss-store-path [valid]: @docroot@/glossary.md#gloss-validity -[substitutes]: @docroot@/glossary.md#gloss-substitute +[store derivation]: @docroot@/glossary.md#gloss-store-derivation +[output paths]: @docroot@/glossary.md#gloss-output-path +[store objects]: @docroot@/glossary.md#gloss-store-object +[closure]: @docroot@/glossary.md#gloss-closure +[substituters]: @docroot@/command-ref/conf-file.md#conf-substituters +[content-addressed derivations]: @docroot@/contributing/experimental-features.md#xp-feature-ca-derivations +[Nix database]: @docroot@/glossary.md#gloss-nix-database -The output path of each derivation is printed on standard output. (For -non-derivations argument, the argument itself is printed.) +The resulting paths are printed on standard output. +For non-derivation arguments, the argument itself is printed. -The following flags are available: +{{#include ../status-build-failure.md}} + +# Options - `--dry-run`\ Print on standard error a description of what packages would be @@ -54,8 +58,6 @@ The following flags are available: previous build, the new output path is left in `/nix/store/name.check.` -{{#include ../status-build-failure.md}} - {{#include ./opt-common.md}} {{#include ../opt-common.md}} @@ -67,8 +69,6 @@ The following flags are available: This operation is typically used to build [store derivation]s produced by [`nix-instantiate`](@docroot@/command-ref/nix-instantiate.md): -[store derivation]: @docroot@/glossary.md#gloss-store-derivation - ```console $ nix-store --realise $(nix-instantiate ./test.nix) /nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1