minion/docs
1
0
Fork 0
forked from auxolotl/docs
Code Pull requests 5 Activity
docs/Nixpkgs/Using-Nixpkgs/overrides.chapter/index.html

2004 lines
49 KiB
HTML
Raw Permalink Normal View History

Deploy cd4936a to pages...pages.gay
2024-07-24 19:14:02 +00:00
<!doctype html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta name="description" content="Aux Documentation">
<meta name="author" content="Nixpkgs Aux, and Lix Contributors">
<link rel="canonical" href="https://docs.auxolotl.org/Nixpkgs/Using-Nixpkgs/overrides.chapter/">
<link rel="prev" href="../overlays.chapter/">
<link rel="next" href="../platform-support.chapter/">
<link rel="icon" href="../../../assets/aux-logo.svg">
<meta name="generator" content="mkdocs-1.6.0, mkdocs-material-9.5.29">
<title>Overriding - Aux Docs</title>
<link rel="stylesheet" href="../../../assets/stylesheets/main.76a95c52.min.css">
<link rel="stylesheet" href="../../../assets/stylesheets/palette.06af60db.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.bunny.net/css?family=IBM+Plex+Sans:300,300i,400,400i,700,700i%7CIBM+Plex+Mono:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"IBM Plex Sans";--md-code-font:"IBM Plex Mono"}</style>
<script>__md_scope=new URL("../../..",location),__md_hash=e=>[...e].reduce((e,_)=>(e<<5)-e+_.charCodeAt(0),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
<meta property="og:type" content="website" >
<meta property="og:title" content="Overriding {#chap-overrides} - Aux Docs" >
<meta property="og:description" content="Aux Documentation" >
<meta property="og:image" content="https://docs.auxolotl.org/assets/images/social/Nixpkgs/Using-Nixpkgs/overrides.chapter.png" >
<meta property="og:image:type" content="image/png" >
<meta property="og:image:width" content="1200" >
<meta property="og:image:height" content="630" >
<meta property="og:url" content="https://docs.auxolotl.org/Nixpkgs/Using-Nixpkgs/overrides.chapter/" >
<meta name="twitter:card" content="summary_large_image" >
<meta name="twitter:title" content="Overriding {#chap-overrides} - Aux Docs" >
<meta name="twitter:description" content="Aux Documentation" >
<meta name="twitter:image" content="https://docs.auxolotl.org/assets/images/social/Nixpkgs/Using-Nixpkgs/overrides.chapter.png" >
</head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="blue">
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#chap-overrides" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<header class="md-header" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="Header">
<a href="../../.." title="Aux Docs" class="md-header__button md-logo" aria-label="Aux Docs" data-md-component="logo">
<img src="../../../assets/aux-logo.svg" alt="logo">
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2Z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
Aux Docs
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
Overriding
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="(prefers-color-scheme: light)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="blue" aria-label="Dark Mode" type="radio" name="__palette" id="__palette_0">
<label class="md-header__button md-icon" title="Dark Mode" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m17.75 4.09-2.53 1.94.91 3.06-2.63-1.81-2.63 1.81.91-3.06-2.53-1.94L12.44 4l1.06-3 1.06 3 3.19.09m3.5 6.91-1.64 1.25.59 1.98-1.7-1.17-1.7 1.17.59-1.98L15.75 11l2.06-.05L18.5 9l.69 1.95 2.06.05m-2.28 4.95c.83-.08 1.72 1.1 1.19 1.85-.32.45-.66.87-1.08 1.27C15.17 23 8.84 23 4.94 19.07c-3.91-3.9-3.91-10.24 0-14.14.4-.4.82-.76 1.27-1.08.75-.53 1.93.36 1.85 1.19-.27 2.86.69 5.83 2.89 8.02a9.96 9.96 0 0 0 8.02 2.89m-1.64 2.02a12.08 12.08 0 0 1-7.8-3.47c-2.17-2.19-3.33-5-3.49-7.82-2.81 3.14-2.7 7.96.31 10.98 3.02 3.01 7.84 3.12 10.98.31Z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: dark)" data-md-color-scheme="slate" data-md-color-primary="indigo" data-md-color-accent="blue" aria-label="Light Mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Light Mode" for="__palette_0" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 7a5 5 0 0 1 5 5 5 5 0 0 1-5 5 5 5 0 0 1-5-5 5 5 0 0 1 5-5m0 2a3 3 0 0 0-3 3 3 3 0 0 0 3 3 3 3 0 0 0 3-3 3 3 0 0 0-3-3m0-7 2.39 3.42C13.65 5.15 12.84 5 12 5c-.84 0-1.65.15-2.39.42L12 2M3.34 7l4.16-.35A7.2 7.2 0 0 0 5.94 8.5c-.44.74-.69 1.5-.83 2.29L3.34 7m.02 10 1.76-3.77a7.131 7.131 0 0 0 2.38 4.14L3.36 17M20.65 7l-1.77 3.79a7.023 7.023 0 0 0-2.38-4.15l4.15.36m-.01 10-4.14.36c.59-.51 1.12-1.14 1.54-1.86.42-.73.69-1.5.83-2.29L20.64 17M12 22l-2.41-3.44c.74.27 1.55.44 2.41.44.82 0 1.63-.17 2.37-.44L12 22Z"/></svg>
</label>
</form>
<script>var media,input,key,value,palette=__md_get("__palette");if(palette&&palette.color){"(prefers-color-scheme)"===palette.color.media&&(media=matchMedia("(prefers-color-scheme: light)"),input=document.querySelector(media.matches?"[data-md-color-media='(prefers-color-scheme: light)']":"[data-md-color-media='(prefers-color-scheme: dark)']"),palette.color.media=input.getAttribute("data-md-color-media"),palette.color.scheme=input.getAttribute("data-md-color-scheme"),palette.color.primary=input.getAttribute("data-md-color-primary"),palette.color.accent=input.getAttribute("data-md-color-accent"));for([key,value]of Object.entries(palette.color))document.body.setAttribute("data-md-color-"+key,value)}</script>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</label>
<nav class="md-search__options" aria-label="Search">
<button type="reset" class="md-search__icon md-icon" title="Clear" aria-label="Clear" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41Z"/></svg>
</button>
</nav>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" tabindex="0" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
Initializing search
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
<div class="md-header__source">
<a href="https://git.auxolotl.org/auxolotl/docs" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M16.777 0a2.9 2.9 0 1 1-2.529 4.322H12.91a4.266 4.266 0 0 0-4.265 4.195v2.118a7.076 7.076 0 0 1 4.147-1.42l.118-.002h1.338a2.9 2.9 0 0 1 5.43 1.422 2.9 2.9 0 0 1-5.43 1.422H12.91a4.266 4.266 0 0 0-4.265 4.195v2.319A2.9 2.9 0 0 1 7.222 24 2.9 2.9 0 0 1 5.8 18.57V8.589a7.109 7.109 0 0 1 6.991-7.108l.118-.001h1.338A2.9 2.9 0 0 1 16.778 0ZM7.223 19.905a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Zm9.554-10.464a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.39Zm0-7.735a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Z"/></svg>
</div>
<div class="md-source__repository">
auxolotl/docs
</div>
</a>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<nav class="md-tabs" aria-label="Tabs" data-md-component="tabs">
<div class="md-grid">
<ul class="md-tabs__list">
<li class="md-tabs__item">
<a href="../../.." class="md-tabs__link">
Aux Documentation Hub
</a>
</li>
<li class="md-tabs__item">
<a href="../../../TODO/" class="md-tabs__link">
TODO
</a>
</li>
<li class="md-tabs__item">
<a href="../../../Aux/" class="md-tabs__link">
Aux
</a>
</li>
<li class="md-tabs__item">
<a href="../../../Lix/" class="md-tabs__link">
Lix
</a>
</li>
<li class="md-tabs__item">
<a href="../../../NixOS/appstream/" class="md-tabs__link">
NixOS
</a>
</li>
<li class="md-tabs__item md-tabs__item--active">
<a href="../../" class="md-tabs__link">
Nixpkgs
</a>
</li>
</ul>
</div>
</nav>
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary md-nav--lifted" aria-label="Navigation" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../../.." title="Aux Docs" class="md-nav__button md-logo" aria-label="Aux Docs" data-md-component="logo">
<img src="../../../assets/aux-logo.svg" alt="logo">
</a>
Aux Docs
</label>
<div class="md-nav__source">
<a href="https://git.auxolotl.org/auxolotl/docs" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M16.777 0a2.9 2.9 0 1 1-2.529 4.322H12.91a4.266 4.266 0 0 0-4.265 4.195v2.118a7.076 7.076 0 0 1 4.147-1.42l.118-.002h1.338a2.9 2.9 0 0 1 5.43 1.422 2.9 2.9 0 0 1-5.43 1.422H12.91a4.266 4.266 0 0 0-4.265 4.195v2.319A2.9 2.9 0 0 1 7.222 24 2.9 2.9 0 0 1 5.8 18.57V8.589a7.109 7.109 0 0 1 6.991-7.108l.118-.001h1.338A2.9 2.9 0 0 1 16.778 0ZM7.223 19.905a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Zm9.554-10.464a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.39Zm0-7.735a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Z"/></svg>
</div>
<div class="md-source__repository">
auxolotl/docs
</div>
</a>
</div>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../.." class="md-nav__link">
<span class="md-ellipsis">
Aux Documentation Hub
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../../TODO/" class="md-nav__link">
<span class="md-ellipsis">
TODO
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../../Aux/" class="md-nav__link">
<span class="md-ellipsis">
Aux
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../../Lix/" class="md-nav__link">
<span class="md-ellipsis">
Lix
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../../NixOS/appstream/" class="md-nav__link">
<span class="md-ellipsis">
NixOS
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--section md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_6" checked>
<div class="md-nav__link md-nav__container">
<a href="../../" class="md-nav__link ">
<span class="md-ellipsis">
Nixpkgs
</span>
</a>
<label class="md-nav__link " for="__nav_6" id="__nav_6_label" tabindex="">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_6_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_6">
<span class="md-nav__icon md-icon"></span>
Nixpkgs
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../options/" class="md-nav__link">
<span class="md-ellipsis">
Options
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Build-Helpers/" class="md-nav__link">
<span class="md-ellipsis">
Build Helpers
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Development/" class="md-nav__link">
<span class="md-ellipsis">
Development
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Functions/" class="md-nav__link">
<span class="md-ellipsis">
Functions
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Hooks/" class="md-nav__link">
<span class="md-ellipsis">
Hooks
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Languages-And-Frameworks/" class="md-nav__link">
<span class="md-ellipsis">
Languages And Frameworks
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Library-Reference/asserts/" class="md-nav__link">
<span class="md-ellipsis">
Library Reference
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Module-System/module-system.chapter/" class="md-nav__link">
<span class="md-ellipsis">
Module System
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Packages/" class="md-nav__link">
<span class="md-ellipsis">
Packages
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--pruned md-nav__item--nested">
<a href="../../Standard-Environment/" class="md-nav__link">
<span class="md-ellipsis">
Standard Environment
</span>
<span class="md-nav__icon md-icon"></span>
</a>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_6_12" checked>
<div class="md-nav__link md-nav__container">
<a href="../" class="md-nav__link ">
<span class="md-ellipsis">
Using Nixpkgs
</span>
</a>
<label class="md-nav__link " for="__nav_6_12" id="__nav_6_12_label" tabindex="0">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_6_12_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_6_12">
<span class="md-nav__icon md-icon"></span>
Using Nixpkgs
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../configuration.chapter/" class="md-nav__link">
<span class="md-ellipsis">
Global configuration
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../overlays.chapter/" class="md-nav__link">
<span class="md-ellipsis">
Overlays
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<label class="md-nav__link md-nav__link--active" for="__toc">
<span class="md-ellipsis">
Overriding
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
Overriding
</span>
</a>
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#sec-pkg-override" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.override
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-pkg-overrideAttrs" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.overrideAttrs
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-pkg-overrideDerivation" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.overrideDerivation
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-lib-makeOverridable" class="md-nav__link">
<span class="md-ellipsis">
lib.makeOverridable
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../platform-support.chapter/" class="md-nav__link">
<span class="md-ellipsis">
Platform Support
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#sec-pkg-override" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.override
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-pkg-overrideAttrs" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.overrideAttrs
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-pkg-overrideDerivation" class="md-nav__link">
<span class="md-ellipsis">
&lt;pkg&gt;.overrideDerivation
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#sec-lib-makeOverridable" class="md-nav__link">
<span class="md-ellipsis">
lib.makeOverridable
</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<h1 id="chap-overrides">Overriding</h1>
<p>Sometimes one wants to override parts of <code>nixpkgs</code>, e.g. derivation attributes, the results of derivations.</p>
<p>These functions are used to make changes to packages, returning only single packages. <a href="#chap-overlays">Overlays</a>, on the other hand, can be used to combine the overridden packages across the entire package set of Nixpkgs.</p>
<h2 id="sec-pkg-override">&lt;pkg&gt;.override</h2>
<p>The function <code>override</code> is usually available for all the derivations in the nixpkgs expression (<code>pkgs</code>).</p>
<p>It is used to override the arguments passed to a function.</p>
<p>Example usages:</p>
<div class="highlight"><pre><span></span><code>pkgs<span class="o">.</span>foo<span class="o">.</span>override <span class="p">{</span> <span class="ss">arg1</span> <span class="o">=</span> val1<span class="p">;</span> <span class="ss">arg2</span> <span class="o">=</span> val2<span class="p">;</span> <span class="cm">/* ... */</span> <span class="p">}</span>
</code></pre></div>
<p>It's also possible to access the previous arguments.</p>
<div class="highlight"><pre><span></span><code>pkgs<span class="o">.</span>foo<span class="o">.</span>override <span class="p">(</span>previous<span class="p">:</span> <span class="p">{</span> <span class="ss">arg1</span> <span class="o">=</span> previous<span class="o">.</span>arg1<span class="p">;</span> <span class="cm">/* ... */</span> <span class="p">})</span>
</code></pre></div>
<!-- TODO: move below programlisting to a new section about extending and overlays and reference it -->
<div class="highlight"><pre><span></span><code><span class="nb">import</span> pkgs<span class="o">.</span>path <span class="p">{</span> <span class="ss">overlays</span> <span class="o">=</span> <span class="p">[</span> <span class="p">(</span>self<span class="p">:</span> super<span class="p">:</span> <span class="p">{</span>
<span class="ss">foo</span> <span class="o">=</span> super<span class="o">.</span>foo<span class="o">.</span>override <span class="p">{</span> <span class="ss">barSupport</span> <span class="o">=</span> <span class="no">true</span> <span class="p">;</span> <span class="p">};</span>
<span class="p">})];}</span>
</code></pre></div>
<div class="highlight"><pre><span></span><code><span class="p">{</span>
<span class="ss">mypkg</span> <span class="o">=</span> pkgs<span class="o">.</span>callPackage <span class="l">./mypkg.nix</span> <span class="p">{</span>
<span class="ss">mydep</span> <span class="o">=</span> pkgs<span class="o">.</span>mydep<span class="o">.</span>override <span class="p">{</span> <span class="cm">/* ... */</span> <span class="p">};</span>
<span class="p">};</span>
<span class="p">}</span>
</code></pre></div>
<p>In the first example, <code>pkgs.foo</code> is the result of a function call with some default arguments, usually a derivation. Using <code>pkgs.foo.override</code> will call the same function with the given new arguments.</p>
<h2 id="sec-pkg-overrideAttrs">&lt;pkg&gt;.overrideAttrs</h2>
<p>The function <code>overrideAttrs</code> allows overriding the attribute set passed to a <code>stdenv.mkDerivation</code> call, producing a new derivation based on the original one. This function is available on all derivations produced by the <code>stdenv.mkDerivation</code> function, which is most packages in the nixpkgs expression <code>pkgs</code>.</p>
<p>Example usages:</p>
<div class="highlight"><pre><span></span><code><span class="p">{</span>
<span class="ss">helloBar</span> <span class="o">=</span> pkgs<span class="o">.</span>hello<span class="o">.</span>overrideAttrs <span class="p">(</span>finalAttrs<span class="p">:</span> previousAttrs<span class="p">:</span> <span class="p">{</span>
<span class="ss">pname</span> <span class="o">=</span> previousAttrs<span class="o">.</span>pname <span class="o">+</span> <span class="s2">&quot;-bar&quot;</span><span class="p">;</span>
<span class="p">});</span>
<span class="p">}</span>
</code></pre></div>
<p>In the above example, "-bar" is appended to the pname attribute, while all other attributes will be retained from the original <code>hello</code> package.</p>
<p>The argument <code>previousAttrs</code> is conventionally used to refer to the attr set originally passed to <code>stdenv.mkDerivation</code>.</p>
<p>The argument <code>finalAttrs</code> refers to the final attributes passed to <code>mkDerivation</code>, plus the <code>finalPackage</code> attribute which is equal to the result of <code>mkDerivation</code> or subsequent <code>overrideAttrs</code> calls.</p>
<p>If only a one-argument function is written, the argument has the meaning of <code>previousAttrs</code>.</p>
<p>Function arguments can be omitted entirely if there is no need to access <code>previousAttrs</code> or <code>finalAttrs</code>.</p>
<div class="highlight"><pre><span></span><code><span class="p">{</span>
<span class="ss">helloWithDebug</span> <span class="o">=</span> pkgs<span class="o">.</span>hello<span class="o">.</span>overrideAttrs <span class="p">{</span>
<span class="ss">separateDebugInfo</span> <span class="o">=</span> <span class="no">true</span><span class="p">;</span>
<span class="p">};</span>
<span class="p">}</span>
</code></pre></div>
<p>In the above example, the <code>separateDebugInfo</code> attribute is overridden to be true, thus building debug info for <code>helloWithDebug</code>.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Note that <code>separateDebugInfo</code> is processed only by the <code>stdenv.mkDerivation</code> function, not the generated, raw Nix derivation. Thus, using <code>overrideDerivation</code> will not work in this case, as it overrides only the attributes of the final derivation. It is for this reason that <code>overrideAttrs</code> should be preferred in (almost) all cases to <code>overrideDerivation</code>, i.e. to allow using <code>stdenv.mkDerivation</code> to process input arguments, as well as the fact that it is easier to use (you can use the same attribute names you see in your Nix code, instead of the ones generated (e.g. <code>buildInputs</code> vs <code>nativeBuildInputs</code>), and it involves less typing).</p>
</div>
<h2 id="sec-pkg-overrideDerivation">&lt;pkg&gt;.overrideDerivation</h2>
<div class="admonition warning">
<p class="admonition-title">Warning</p>
<p>You should prefer <code>overrideAttrs</code> in almost all cases, see its documentation for the reasons why. <code>overrideDerivation</code> is not deprecated and will continue to work, but is less nice to use and does not have as many abilities as <code>overrideAttrs</code>.</p>
</div>
<div class="admonition warning">
<p class="admonition-title">Warning</p>
<p>Do not use this function in Nixpkgs as it evaluates a derivation before modifying it, which breaks package abstraction. In addition, this evaluation-per-function application incurs a performance penalty, which can become a problem if many overrides are used. It is only intended for ad-hoc customisation, such as in <code>~/.config/nixpkgs/config.nix</code>.</p>
</div>
<p>The function <code>overrideDerivation</code> creates a new derivation based on an existing one by overriding the original's attributes with the attribute set produced by the specified function. This function is available on all derivations defined using the <code>makeOverridable</code> function. Most standard derivation-producing functions, such as <code>stdenv.mkDerivation</code>, are defined using this function, which means most packages in the nixpkgs expression, <code>pkgs</code>, have this function.</p>
<p>Example usage:</p>
<div class="highlight"><pre><span></span><code><span class="p">{</span>
<span class="ss">mySed</span> <span class="o">=</span> pkgs<span class="o">.</span>gnused<span class="o">.</span>overrideDerivation <span class="p">(</span>oldAttrs<span class="p">:</span> <span class="p">{</span>
<span class="ss">name</span> <span class="o">=</span> <span class="s2">&quot;sed-4.2.2-pre&quot;</span><span class="p">;</span>
<span class="ss">src</span> <span class="o">=</span> fetchurl <span class="p">{</span>
<span class="ss">url</span> <span class="o">=</span> <span class="s2">&quot;ftp://alpha.gnu.org/gnu/sed/sed-4.2.2-pre.tar.bz2&quot;</span><span class="p">;</span>
<span class="ss">hash</span> <span class="o">=</span> <span class="s2">&quot;sha256-MxBJRcM2rYzQYwJ5XKxhXTQByvSg5jZc5cSHEZoB2IY=&quot;</span><span class="p">;</span>
<span class="p">};</span>
<span class="ss">patches</span> <span class="o">=</span> <span class="p">[];</span>
<span class="p">});</span>
<span class="p">}</span>
</code></pre></div>
<p>In the above example, the <code>name</code>, <code>src</code>, and <code>patches</code> of the derivation will be overridden, while all other attributes will be retained from the original derivation.</p>
<p>The argument <code>oldAttrs</code> is used to refer to the attribute set of the original derivation.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>A package's attributes are evaluated <em>before</em> being modified by the <code>overrideDerivation</code> function. For example, the <code>name</code> attribute reference in <code>url = "mirror://gnu/hello/${name}.tar.gz";</code> is filled-in <em>before</em> the <code>overrideDerivation</code> function modifies the attribute set. This means that overriding the <code>name</code> attribute, in this example, <em>will not</em> change the value of the <code>url</code> attribute. Instead, we need to override both the <code>name</code> <em>and</em> <code>url</code> attributes.</p>
</div>
<h2 id="sec-lib-makeOverridable">lib.makeOverridable</h2>
<p>The function <code>lib.makeOverridable</code> is used to make the result of a function easily customizable. This utility only makes sense for functions that accept an argument set and return an attribute set.</p>
<p>Example usage:</p>
<div class="highlight"><pre><span></span><code><span class="p">{</span>
<span class="ss">f</span> <span class="o">=</span> <span class="p">{</span> a<span class="p">,</span> b <span class="p">}:</span> <span class="p">{</span> <span class="ss">result</span> <span class="o">=</span> a<span class="o">+</span>b<span class="p">;</span> <span class="p">};</span>
<span class="ss">c</span> <span class="o">=</span> lib<span class="o">.</span>makeOverridable f <span class="p">{</span> <span class="ss">a</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span> <span class="ss">b</span> <span class="o">=</span> <span class="mi">2</span><span class="p">;</span> <span class="p">};</span>
<span class="p">}</span>
</code></pre></div>
<p>The variable <code>c</code> is the value of the <code>f</code> function applied with some default arguments. Hence the value of <code>c.result</code> is <code>3</code>, in this example.</p>
<p>The variable <code>c</code> however also has some additional functions, like
<a href="#sec-pkg-override">c.override</a> which can be used to override the
default arguments. In this example the value of
<code>(c.override { a = 4; }).result</code> is 6.</p>
</article>
</div>
<script>var target=document.getElementById(location.hash.slice(1));target&&target.name&&(target.checked=target.name.startsWith("__tabbed_"))</script>
</div>
</main>
<footer class="md-footer">
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
<div class="md-copyright__highlight">
Licenced MIT
</div>
Made with
<a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
Material for MkDocs
</a>
</div>
<div class="md-social">
<a href="https://git.auxolotl.org/auxolotl/docs" target="_blank" rel="noopener" title="Aux Docs Repo" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M16.777 0a2.9 2.9 0 1 1-2.529 4.322H12.91a4.266 4.266 0 0 0-4.265 4.195v2.118a7.076 7.076 0 0 1 4.147-1.42l.118-.002h1.338a2.9 2.9 0 0 1 5.43 1.422 2.9 2.9 0 0 1-5.43 1.422H12.91a4.266 4.266 0 0 0-4.265 4.195v2.319A2.9 2.9 0 0 1 7.222 24 2.9 2.9 0 0 1 5.8 18.57V8.589a7.109 7.109 0 0 1 6.991-7.108l.118-.001h1.338A2.9 2.9 0 0 1 16.778 0ZM7.223 19.905a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Zm9.554-10.464a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.39Zm0-7.735a1.194 1.194 0 1 0 0 2.389 1.194 1.194 0 0 0 0-2.389Z"/></svg>
</a>
<a href="https://forum.aux.computer/" target="_blank" rel="noopener" title="Aux Forum" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12.103 0C18.666 0 24 5.485 24 11.997c0 6.51-5.33 11.99-11.9 11.99L0 24V11.79C0 5.28 5.532 0 12.103 0zm.116 4.563a7.395 7.395 0 0 0-6.337 3.57 7.247 7.247 0 0 0-.148 7.22L4.4 19.61l4.794-1.074a7.424 7.424 0 0 0 8.136-1.39 7.256 7.256 0 0 0 1.737-7.997 7.375 7.375 0 0 0-6.84-4.585h-.008z"/></svg>
</a>
<a href="https://wiki.auxolotl.org/" target="_blank" rel="noopener" title="Aux Wiki" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M17.801 13.557c.148.098.288.202.417.313 1.854 1.6 3.127 4.656 2.582 7.311-1.091-.255-5.747-1.055-7.638-3.383-.91-1.12-1.366-2.081-1.569-2.885a5.65 5.65 0 0 0 .034-.219c.089.198.197.35.313.466.24.24.521.335.766.372.304.046.594-.006.806-.068l.001.001c.05-.015.433-.116.86-.342.325-.173 2.008-.931 3.428-1.566Zm-7.384 1.435C9.156 16.597 6.6 18.939.614 18.417c.219-1.492 1.31-3.019 2.51-4.11.379-.345.906-.692 1.506-1.009.286.168.598.332.939.486 2.689 1.221 3.903 1.001 4.89.573a1.3 1.3 0 0 0 .054-.025 6.156 6.156 0 0 0-.096.66Zm4.152-.462c.38-.341.877-.916 1.383-1.559-.389-.15-.866-.371-1.319-.591-.598-.29-1.305-.283-2.073-.315a4.685 4.685 0 0 1-.804-.103c.014-.123.027-.246.038-.369.062.104.673.057.871.057.354 0 1.621.034 3.074-.574 1.452-.608 2.55-1.706 3.022-3.225.474-1.52.22-3.091-.168-3.952-.169.709-1.453 2.381-1.926 2.871-.473.489-2.381 2.296-2.972 2.921-.7.74-.688.793-1.332 1.302-.202.19-.499.402-.563.53.027-.338.039-.675.027-.997a7.653 7.653 0 0 0-.032-.523c.322-.059.567-.522.567-.861 0-.224-.106-.247-.271-.229.075-.894.382-3.923 1.254-4.281.218.109.831.068.649-.295-.182-.364-.825-.074-1.081.266-.28.374-.956 2.046-.92 4.324-.113.014-.174.033-.322.033-.171 0-.321-.04-.433-.05.034-2.275-.714-3.772-.84-4.169-.12-.375-.491-.596-.781-.596-.146 0-.272.056-.333.179-.182.363.459.417.677.308.706.321 1.156 3.519 1.254 4.277-.125-.006-.199.035-.199.233 0 .311.17.756.452.843a.442.442 0 0 0-.007.03s-.287.99-.413 2.189a4.665 4.665 0 0 1-.718-.225c-.714-.286-1.355-.583-2.019-.566-.664.018-1.366.023-1.804-.036-.438-.058-.649-.15-.649-.15s-.234.365.257 1.075c.42.607 1.055 1.047 1.644 1.18.589.134 1.972.18 2.785-.377.16-.109.317-.228.459-.34a8.717 8.717 0 0 0-.013.626c-.289.753-.571 1.993-.268 3.338 0-.001.701-.842.787-2.958.006-.144.009-.271.01-.383.052-.248.103-.518.148-.799.072.135.151.277.234.413.511.842 1.791 1.37 2.383 1.49.091.019.187.032.285.038Zm-1.12.745c-.188.055-.445.1-.713.059-.21-.031-.45-.11-.655-.316-.169-.168-.312-.419-.401-.789a9.837 9.837 0 0 0 .039-.82l.049-.243c.563.855 1.865 1.398 2.476 1.522.036.008.072.014.109.02l-.013.009c-.579.415-.76.503-.891.558Zm6.333-2.818c-.257.114-4.111 1.822-5.246 2.363.98-.775 3.017-3.59 3.699-4.774 1.062.661 1.468 1.109 1.623 1.441.101.217.09.38.096.515a.57.57 0 0 1-.172.455Zm-9.213 1.62a1.606 1.606 0 0 1-.19.096c-.954.414-2.126.61-4.728-.571-2.023-.918-3.024-2.157-3.371-2.666.476.161 1.471.473 2.157.524.282.021.703.068 1.167.125.021.209.109.486.345.829l.001.001c.451.651 1.134 1.119 1.765 1.262.622.141 2.083.182 2.942-.407a3.12 3.12 0 0 0 .132-.093l.001.179a6.052 6.052 0 0 0-.221.721Zm5.512-1.271a17.49 17.49 0 0 1-1.326-.589c.437.042 1.054.083 1.692.108-.121.162-.244.323-.366.481Zm.932-1.26c-.12.17-.245.343-.373.517-.241.018-.478.03-.709.038a29.05 29.05 0 0 1-.741-.048c.608-.065 1.228-.252 1.823-.507Zm.22-.315c-.809.382-1.679.648-2.507.648-.472 0-.833.018-1.139.039v.001c-.324-.031-.665-.039-1.019-.054a3.555 3.555 0 0 1-.152-.009c.102-.002.192-.006.249-.006.363 0 1.662.034 3.151-.589 1.508-.632 2.645-1.773 3.136-3.351.37-1.186.31-2.402.086-3.312.458-.336.86-.651 1.147-.91.501-.451.743-.733.848-.869.199.206.714.864.685 2.138-.036 1.611-.606 3.187-1.501 4.154a9.099 9.099 0 0 1-1.321 1.132 11.978 11.978 0 0 0-.644-.422l-.089-.055-.051.091c-.184.332-.5.825-.879 1.374ZM4.763 5.817c-.157 1.144.113 2.323.652 3.099.539.776 2.088 2.29 3.614 2.505.991.14 2.055.134 2.055.134s-.593-.576-1.114-1.66c-.521-1.085-.948-2.104-1.734-2.786-.785-.681-1.601-1.416-2.045-1.945-.444-.53-.59-.86-.59-.86s-.656.175-.838 1.513Zm14.301 4.549a9.162 9.162 0 0 0 1.3-1.12c.326-.352.611-.782.845-1.265 1.315.145 2.399.371 2.791.434 0 0-.679 1.971-3.945 3.022l-.016-.035c-.121-.26-.385-.594-.975-1.036Zm-11.634.859a8.537 8.537 0 0 1-.598-.224c-1.657-.693-2.91-1.944-3.449-3.678-.498-1.601-.292-3.251.091-4.269.225.544.758 1.34 1.262 2.01a3.58 3.58 0 0 0-.172.726c-.163 1.197.123 2.428.687 3.24.416.599 1.417 1.62 2.555 2.193-.128.002-.253.003-.376.002Zm-1.758-.077c-.958-.341-1.901-.787-2.697-1.368C-.07 7.559 0 6.827 0 6.827s1.558-.005 3.088.179c.03.126.065.
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"base": "../../..", "features": ["content.tooltips", "search.highlight", "navigation.tabs", "navigation.indexes", "navigation.prune"], "search": "../../../assets/javascripts/workers/search.b8dbb3d2.min.js", "translations": {"clipboard.copied": "Copied to clipboard", "clipboard.copy": "Copy to clipboard", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.placeholder": "Type to start searching", "search.result.term.missing": "Missing", "select.version": "Select version"}}</script>
<script src="../../../assets/javascripts/bundle.fe8b6f2b.min.js"></script>
</body>
</html>
Copy permalink