Low-level derivations - Revision history

DoggoBit: Switched more args to named

2025-06-14T19:27:21Z

Switched more args to named

← Older revision		Revision as of 19:27, 14 June 2025
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	=== Standard environment ===		=== Standard environment ===

	For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code>{{cite manual\|nixpkgs\|sec-using-stdenv\|Using stdenv}} gives us access to the common Linux utilities pre-included for us{{cite manual\|nixpkgs\|sec-tools-of-stdenv\|Tools provided by stdenv}}, so we don't have to do the package importing ourselves:		For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code>{{cite manual\|nixpkgs\|sec-using-stdenv\|title=Using stdenv}} gives us access to the common Linux utilities pre-included for us{{cite manual\|nixpkgs\|sec-tools-of-stdenv\|title=Tools provided by stdenv}}, so we don't have to do the package importing ourselves:

	{{File\|example.nix\|nix\|highlight=3\|		{{File\|example.nix\|nix\|highlight=3\|
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	=== Nixpkgs utilities ===		=== Nixpkgs utilities ===

	Even further up the chain of abstractions, [[Nixpkgs]] contains many pre-built utilities for us that handle some of the configuration involved in the standard environment as well. In our case, we can use the <code>writeShellScript</code>{{cite manual\|nixpkgs\|trivial-builder-writeShellScript\|writeShellScript}}:		Even further up the chain of abstractions, [[Nixpkgs]] contains many pre-built utilities for us that handle some of the configuration involved in the standard environment as well. In our case, we can use the <code>writeShellScript</code>{{cite manual\|nixpkgs\|trivial-builder-writeShellScript\|title=writeShellScript}}:

	{{File\|example.nix\|nix\|		{{File\|example.nix\|nix\|

DoggoBit: Switch arguments to named

2025-06-14T19:26:38Z

Switch arguments to named

← Older revision		Revision as of 19:26, 14 June 2025
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	{{File\|example.sh\|bash\|#!/bin/bash		{{File\|example.sh\|bash\|#!/bin/bash
	echo "Hello, world!"}}		echo "Hello, world!"}}
	When running this script (e.g. <code>$ ./example.sh</code>) we'll get exactly the output we want. However, we're trying to build the script using Nix. Our first approach might be to write a simple derivation{{cite manual\|nix\|language/derivations\|5.4.1\|Derivations}} similar to:		When running this script (e.g. <code>$ ./example.sh</code>) we'll get exactly the output we want. However, we're trying to build the script using Nix. Our first approach might be to write a simple derivation{{cite manual\|nix\|language/derivations\|number=5.4.1\|title=Derivations}} similar to:
	{{File\|example.nix\|nix\|<nowiki>derivation {		{{File\|example.nix\|nix\|<nowiki>derivation {
	name = "hello-world";		name = "hello-world";

DoggoBit: fix display

2025-06-10T15:53:29Z

fix display

← Older revision		Revision as of 15:53, 10 June 2025
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	{{external\|The Nix Reference Manual\|§ 5.4.1. {{manual\|nix\|language/derivations}}}}		{{external\|The Nix Reference Manual\|§ 5.4.1. {{manual\|nix\|language/derivations\|Derivations}}}}
	Writing '''low-level derivations''' without the convenience of the [[standard environment]] requires understanding the core fundamentals of how [[Nix]] works. While writing [[derivations]] in this manner is not common, they can be useful when no utility present in the standard environment matches the required use case, as well as being an essential learning tool for understanding why <code>stdenv.mkDerivation</code> is needed in most cases.		Writing '''low-level derivations''' without the convenience of the [[standard environment]] requires understanding the core fundamentals of how [[Nix]] works. While writing [[derivations]] in this manner is not common, they can be useful when no utility present in the standard environment matches the required use case, as well as being an essential learning tool for understanding why <code>stdenv.mkDerivation</code> is needed in most cases.

DoggoBit at 15:53, 10 June 2025

2025-06-10T15:53:11Z

← Older revision		Revision as of 15:53, 10 June 2025
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			{{external\|The Nix Reference Manual\|§ 5.4.1. {{manual\|nix\|language/derivations}}}}
	Writing '''low-level derivations''' without the convenience of the [[standard environment]] requires understanding the core fundamentals of how [[Nix]] works. While writing [[derivations]] in this manner is not common, they can be useful when no utility present in the standard environment matches the required use case, as well as being an essential learning tool for understanding why <code>stdenv.mkDerivation</code> is needed in most cases.		Writing '''low-level derivations''' without the convenience of the [[standard environment]] requires understanding the core fundamentals of how [[Nix]] works. While writing [[derivations]] in this manner is not common, they can be useful when no utility present in the standard environment matches the required use case, as well as being an essential learning tool for understanding why <code>stdenv.mkDerivation</code> is needed in most cases.

DoggoBit: /* A Hello, world example */ cite derivations from manual

2025-06-10T15:38:09Z

A Hello, world example: cite derivations from manual

← Older revision		Revision as of 15:38, 10 June 2025
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	{{File\|example.sh\|bash\|#!/bin/bash		{{File\|example.sh\|bash\|#!/bin/bash
	echo "Hello, world!"}}		echo "Hello, world!"}}
	When running this script (e.g. <code>$ ./example.sh</code>) we'll get exactly the output we want. However, we're trying to build the script using Nix. Our first approach might be to write a simple derivation similar to:		When running this script (e.g. <code>$ ./example.sh</code>) we'll get exactly the output we want. However, we're trying to build the script using Nix. Our first approach might be to write a simple derivation{{cite manual\|nix\|language/derivations\|5.4.1\|Derivations}} similar to:
	{{File\|example.nix\|nix\|<nowiki>derivation {		{{File\|example.nix\|nix\|<nowiki>derivation {
	name = "hello-world";		name = "hello-world";

DoggoBit: /* Nixpkgs utilities */ cite writeShellScript

2025-06-10T15:33:45Z

Nixpkgs utilities: cite writeShellScript

← Older revision		Revision as of 15:33, 10 June 2025
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	=== Nixpkgs utilities ===		=== Nixpkgs utilities ===

	Even further up the chain of abstractions, [[Nixpkgs]] contains many pre-built utilities for us that handle some of the configuration involved in the standard environment as well. In our case, we can use the <code>writeShellScript</code>:		Even further up the chain of abstractions, [[Nixpkgs]] contains many pre-built utilities for us that handle some of the configuration involved in the standard environment as well. In our case, we can use the <code>writeShellScript</code>{{cite manual\|nixpkgs\|trivial-builder-writeShellScript\|writeShellScript}}:

	{{File\|example.nix\|nix\|		{{File\|example.nix\|nix\|

DoggoBit: /* Standard environment */ cite mkDerivation

2025-06-10T15:31:20Z

Standard environment: cite mkDerivation

← Older revision		Revision as of 15:31, 10 June 2025
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	=== Standard environment ===		=== Standard environment ===

	For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code> gives us access to the common Linux utilities pre-included for us{{cite manual\|nixpkgs\|sec-tools-of-stdenv\|Tools provided by stdenv}}, so we don't have to do the package importing ourselves:		For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code>{{cite manual\|nixpkgs\|sec-using-stdenv\|Using stdenv}} gives us access to the common Linux utilities pre-included for us{{cite manual\|nixpkgs\|sec-tools-of-stdenv\|Tools provided by stdenv}}, so we don't have to do the package importing ourselves:

	{{File\|example.nix\|nix\|highlight=3\|		{{File\|example.nix\|nix\|highlight=3\|

DoggoBit: include references

2025-06-10T15:21:33Z

include references

← Older revision		Revision as of 15:21, 10 June 2025
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	''		''
	}}		}}

			{{references}}

DoggoBit: /* Standard environment */ Cite Nixpkgs manual

2025-06-10T15:21:02Z

Standard environment: Cite Nixpkgs manual

← Older revision		Revision as of 15:21, 10 June 2025
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	=== Standard environment ===		=== Standard environment ===

	For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code> gives us access to the common Linux utilities pre-included for us, so we don't have to do the package importing ourselves:		For practicality purposes, let's compare this to the standard environment way of doing this. Using <code>stdenv.mkDerivation</code> gives us access to the common Linux utilities pre-included for us{{cite manual\|nixpkgs\|sec-tools-of-stdenv\|Tools provided by stdenv}}, so we don't have to do the package importing ourselves:

	{{File\|example.nix\|nix\|highlight=3\|		{{File\|example.nix\|nix\|highlight=3\|

DoggoBit: /* A Hello, world example */ Fix typo

2025-06-09T20:22:29Z

A Hello, world example: Fix typo

← Older revision		Revision as of 20:22, 9 June 2025
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	Building the package again, we'll come across another surprising error:		Building the package again, we'll come across another surprising error:

	{{code\|~~lines~~=no\|lang=console\|highlight=8\|		{{code\|line=no\|lang=console\|highlight=8\|
	$ nix-build example.nix		$ nix-build example.nix
	this derivation will be built:		this derivation will be built:
Line 80:		Line 80:
	Turns out <code>chmod</code> is not part of our build environment either; that's how minimal the low-level derivation environment is! However, before we fix the script in a similar manner, let's observe another important detail: the store path. Compare the build location of this example, and the previous one; the SHAs are different! That is because our derivation has different inputs to the one before, therefore it's built under a different location in the Nix store. And to highlight this, without fixing the script, let's build it again:		Turns out <code>chmod</code> is not part of our build environment either; that's how minimal the low-level derivation environment is! However, before we fix the script in a similar manner, let's observe another important detail: the store path. Compare the build location of this example, and the previous one; the SHAs are different! That is because our derivation has different inputs to the one before, therefore it's built under a different location in the Nix store. And to highlight this, without fixing the script, let's build it again:

	{{code\|~~lines~~=no\|lang=console\|highlight=3\|		{{code\|line=no\|lang=console\|highlight=3\|
	$ nix-build example.nix		$ nix-build example.nix
	this derivation will be built:		this derivation will be built: