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Merge pull request #8741 from ncfavier/clarify-rl-notes-nested-attrs-merge
doc: clarify release notes about nested attribute merges
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484c820c48
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@ -11,8 +11,12 @@
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```nix
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```nix
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{
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{
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nested = { foo = 1; };
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nested = {
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nested = { ${"ba" + "r"} = 2; };
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foo = 1;
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};
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nested = {
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${"ba" + "r"} = 2;
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};
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}
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}
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```
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```
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@ -22,8 +26,17 @@
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{ nested = { bar = 2; foo = 1; }; }
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{ nested = { bar = 2; foo = 1; }; }
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```
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```
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Note that the feature of merging multiple attribute set declarations is of questionable value.
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Note that the feature of merging multiple *full declarations* of attribute sets like `nested` in the example is of questionable value.
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It allows writing expressions that are very hard to read, for instance when there are many lines of code between two declarations of the same attribute.
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It allows writing expressions that are very hard to read, for instance when there are many lines of code between two declarations of the same attribute.
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This has been around for a long time and is therefore supported for backwards compatibility, but should not be relied upon.
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This has been around for a long time and is therefore supported for backwards compatibility, but should not be relied upon.
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Instead, consider using the *nested attribute path* syntax:
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```nix
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{
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nested.foo = 1;
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nested.${"ba" + "r"} = 2;
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}
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```
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* Tarball flakes can now redirect to an "immutable" URL that will be recorded in lock files. This allows the use of "mutable" tarball URLs like `https://example.org/hello/latest.tar.gz` in flakes. See the [tarball fetcher](../protocols/tarball-fetcher.md) for details.
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* Tarball flakes can now redirect to an "immutable" URL that will be recorded in lock files. This allows the use of "mutable" tarball URLs like `https://example.org/hello/latest.tar.gz` in flakes. See the [tarball fetcher](../protocols/tarball-fetcher.md) for details.
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