NixOS/nix

`derivationOf` primop

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#10,120 创建于 2024年3月1日

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描述

Is your feature request related to a problem? Please describe.

It behaves roughly as an inverse of outputOf and is equivalent to the planned ^.. syntax on the CLI.

This function improves RFC 92 and multi-derivation package support, by allowing the derivation path to be accessed for any output, whose derivations may be distinct, rather than only exposing a single drvPath.

pkg.drvPath is rarely needed. When we have a function for it, this attribute can be removed from the packages.

https://github.com/NixOS/nixpkgs/pull/281536 adds such a function in Nixpkgs. Its implementation can serve as a polyfill for this builtin.

Describe the solution you'd like

A primop that takes the Nix language representation of a DerivingPath, a string with context, and returns the deriver field if it is present. Otherwise it should throw or return null.

Describe alternatives you've considered

Require the Nixpkgs library for this functionality.

Additional context

  • #10121

Priorities

Add :+1: to issues you find important.

贡献者指南

技术栈
cpp
领域
build systemdeveloper experience
议题类型
feature
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
5
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
over 1 week
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
fresh
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
Understanding of Nix language evaluationFamiliarity with Nix derivation modelC++ programming experienceKnowledge of string contexts in Nix
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
20
研究方向
The implementation should follow the approach of the existing `outputOf` primop, handling `DerivingPath` and the deriver field. The nixpkgs PR #281536 provides a polyfill implementation in Nix that can guide the design. The linked issue #10121 discusses related concepts. Key files to examine include the primop definitions in the Nix interpreter source (e.g., `src/libexpr/primops.cc`) and the handling of string contexts.