Merge pull request #135 from DeterminateSystems/sync-2.30.0

Sync with upstream 2.30.0

Author: cole-h

.gitignore

@@ -47,3 +47,6 @@ result-*
 .DS_Store
 
 flake-regressions
+
+# direnv
+.direnv/

.mergify.yml

@@ -139,3 +139,14 @@ pull_request_rules:
         labels:
           - automatic backport
           - merge-queue
+
+  - name: backport patches to 2.29
+    conditions:
+      - label=backport 2.29-maintenance
+    actions:
+      backport:
+        branches:
+          - "2.29-maintenance"
+        labels:
+          - automatic backport
+          - merge-queue

.version

@@ -1 +1 @@
-2.29.1
+2.30.0

doc/manual/source/SUMMARY.md.in

@@ -52,6 +52,7 @@
   - [Tuning Cores and Jobs](advanced-topics/cores-vs-jobs.md)
   - [Verifying Build Reproducibility](advanced-topics/diff-hook.md)
   - [Using the `post-build-hook`](advanced-topics/post-build-hook.md)
+  - [Evaluation profiler](advanced-topics/eval-profiler.md)
 - [Command Reference](command-ref/index.md)
   - [Common Options](command-ref/opt-common.md)
   - [Common Environment Variables](command-ref/env-common.md)
@@ -147,6 +148,7 @@
   - [Release 3.0.0 (2025-03-04)](release-notes-determinate/rl-3.0.0.md)
 - [Nix Release Notes](release-notes/index.md)
 {{#include ./SUMMARY-rl-next.md}}
+  - [Release 2.30 (2025-07-07)](release-notes/rl-2.30.md)
   - [Release 2.29 (2025-05-14)](release-notes/rl-2.29.md)
   - [Release 2.28 (2025-04-02)](release-notes/rl-2.28.md)
   - [Release 2.27 (2025-03-03)](release-notes/rl-2.27.md)

doc/manual/source/advanced-topics/eval-profiler.md

@@ -0,0 +1,33 @@
+# Using the `eval-profiler`
+
+Nix evaluator supports [evaluation](@docroot@/language/evaluation.md)
+[profiling](<https://en.wikipedia.org/wiki/Profiling_(computer_programming)>)
+compatible with `flamegraph.pl`. The profiler samples the nix
+function call stack at regular intervals. It can be enabled with the
+[`eval-profiler`](@docroot@/command-ref/conf-file.md#conf-eval-profiler)
+setting:
+
+```console
+$ nix-instantiate "<nixpkgs>" -A hello --eval-profiler flamegraph
+```
+
+Stack sampling frequency and the output file path can be configured with
+[`eval-profile-file`](@docroot@/command-ref/conf-file.md#conf-eval-profile-file)
+and [`eval-profiler-frequency`](@docroot@/command-ref/conf-file.md#conf-eval-profiler-frequency).
+By default the collected profile is saved to `nix.profile` file in the current working directory.
+
+The collected profile can be directly consumed by `flamegraph.pl`:
+
+```console
+$ flamegraph.pl nix.profile > flamegraph.svg
+```
+
+The line information in the profile contains the location of the [call
+site](https://en.wikipedia.org/wiki/Call_site) position and the name of the
+function being called (when available). For example:
+
+```
+/nix/store/x9wnkly3k1gkq580m90jjn32q9f05q2v-source/pkgs/top-level/default.nix:167:5:primop import
+```
+
+Here `import` primop is called at `/nix/store/x9wnkly3k1gkq580m90jjn32q9f05q2v-source/pkgs/top-level/default.nix:167:5`.

doc/manual/source/command-ref/nix-channel.md

@@ -59,6 +59,11 @@ This command has the following operations:
   Download the Nix expressions of subscribed channels and create a new generation.
   Update all channels if none is specified, and only those included in *names* otherwise.
 
+  > **Note**
+  >
+  > Downloaded channel contents are cached.
+  > Use `--tarball-ttl` or the [`tarball-ttl` configuration option](@docroot@/command-ref/conf-file.md#conf-tarball-ttl) to change the validity period of cached downloads.
+
 - `--list-generations`
 
   Prints a list of all the current existing generations for the

doc/manual/source/glossary.md

@@ -31,9 +31,22 @@
 
   The industry term for storage and retrieval systems using [content addressing](#gloss-content-address). A Nix store also has [input addressing](#gloss-input-addressed-store-object), and metadata.
 
+- [derivation]{#gloss-derivation}
+
+  A derivation can be thought of as a [pure function](https://en.wikipedia.org/wiki/Pure_function) that produces new [store objects][store object] from existing store objects.
+
+  Derivations are implemented as [operating system processes that run in a sandbox](@docroot@/store/building.md#builder-execution).
+  This sandbox by default only allows reading from store objects specified as inputs, and only allows writing to designated [outputs][output] to be [captured as store objects](@docroot@/store/building.md#processing-outputs).
+
+  A derivation is typically specified as a [derivation expression] in the [Nix language], and [instantiated][instantiate] to a [store derivation].
+  There are multiple ways of obtaining store objects from store derivatons, collectively called [realisation][realise].
+
+  [derivation]: #gloss-derivation
+
 - [store derivation]{#gloss-store-derivation}
 
-  A single build task.
+  A [derivation] represented as a [store object].
+
   See [Store Derivation](@docroot@/store/derivation/index.md#store-derivation) for details.
 
   [store derivation]: #gloss-store-derivation
@@ -57,10 +70,7 @@
 
 - [derivation expression]{#gloss-derivation-expression}
 
-  A description of a [store derivation] in the Nix language.
-  The output(s) of a derivation are store objects.
-  Derivations are typically specified in Nix expressions using the [`derivation` primitive](./language/derivations.md).
-  These are translated into store layer *derivations* (implicitly by `nix-env` and `nix-build`, or explicitly by `nix-instantiate`).
+  A description of a [store derivation] using the [`derivation` primitive](./language/derivations.md) in the [Nix language].
 
   [derivation expression]: #gloss-derivation-expression
 

doc/manual/source/language/advanced-attributes.md

@@ -53,23 +53,13 @@ Derivations can declare some infrequently used optional attributes.
 
   - [`__structuredAttrs`]{#adv-attr-structuredAttrs}\
     If the special attribute `__structuredAttrs` is set to `true`, the other derivation
-    attributes are serialised into a file in JSON format. The environment variable
-    `NIX_ATTRS_JSON_FILE` points to the exact location of that file both in a build
-    and a [`nix-shell`](../command-ref/nix-shell.md). This obviates the need for
-    [`passAsFile`](#adv-attr-passAsFile) since JSON files have no size restrictions,
-    unlike process environments.
-
-    It also makes it possible to tweak derivation settings in a structured way; see
-    [`outputChecks`](#adv-attr-outputChecks) for example.
-
-    As a convenience to Bash builders,
-    Nix writes a script that initialises shell variables
-    corresponding to all attributes that are representable in Bash. The
-    environment variable `NIX_ATTRS_SH_FILE` points to the exact
-    location of the script, both in a build and a
-    [`nix-shell`](../command-ref/nix-shell.md). This includes non-nested
-    (associative) arrays. For example, the attribute `hardening.format = true`
-    ends up as the Bash associative array element `${hardening[format]}`.
+    attributes are serialised into a file in JSON format.
+
+    This obviates the need for [`passAsFile`](#adv-attr-passAsFile) since JSON files have no size restrictions, unlike process environments.
+    It also makes it possible to tweak derivation settings in a structured way;
+    see [`outputChecks`](#adv-attr-outputChecks) for example.
+
+    See the [corresponding section in the derivation page](@docroot@/store/derivation/index.md#structured-attrs) for further details.
 
     > **Warning**
     >

doc/manual/source/language/index.md

@@ -1,6 +1,6 @@
 # Nix Language
 
-The Nix language is designed for conveniently creating and composing *derivations* – precise descriptions of how contents of existing files are used to derive new files.
+The Nix language is designed for conveniently creating and composing [derivations](@docroot@/glossary.md#gloss-derivation) – precise descriptions of how contents of existing files are used to derive new files.
 
 > **Tip**
 >

doc/manual/source/language/operators.md

@@ -196,7 +196,7 @@ All comparison operators are implemented in terms of `<`, and the following equi
 
 ## Logical implication
 
-Equivalent to `!`*b1* `||` *b2*.
+Equivalent to `!`*b1* `||` *b2*  (or `if` *b1* `then` *b2* `else true`)
 
 [Logical implication]: #logical-implication