# Merkle trees and build systems \[LWN.net\]
**URL:** https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429
**Category:** Links
**Created:** [May 30, 2020, 9:22am UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429 "2020-05-30T09:22:52Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@b42](https://discourse.nixos.org/u/b42)
#### Post date: [May 30, 2020, 9:22am UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/1 "2020-05-30T09:22:52Z")
> **[Merkle trees and build systems \[LWN.net\]](https://lwn.net/Articles/821367/)**
>
> In traditional build tools like Make, targets and dependencies are always
> files. Imagine if you could specify an entire tree (directory) as a
> dependency: You could exhaustively specify a "build root" filesystem containing
> the toolchain used for...
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### Author:  [@Ericson2314](https://discourse.nixos.org/u/Ericson2314)
#### Post date: [May 30, 2020, 5:01pm UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/2 "2020-05-30T17:01:49Z")
Ah, if the rest of the world gets used to working with trees not individual files, we could have a really good `ninja2nix` without uncovering tons of impurities in practice.
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### Author:  [@Ericson2314](https://discourse.nixos.org/u/Ericson2314)
#### Post date: [May 30, 2020, 5:16pm UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/3 "2020-05-30T17:16:44Z")
And this has tons of left over with [Obsidian Systems is excited to bring IPFS support to Nix](https://discourse.nixos.org/t/obsidian-systems-is-excited-to-bring-ipfs-support-to-nix/7375) . I left a comment to that effect on the article (current awaiting moderation); would love to compare notes.
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### Author:  [@pasqui23](https://discourse.nixos.org/u/pasqui23)
#### Post date: [May 31, 2020, 11:42am UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/4 "2020-05-31T11:42:42Z")
> **[GitHub - awakesecurity/ninja2nix: A tool that generates a Nix derivation from...](https://github.com/awakesecurity/ninja2nix)**
>
> A tool that generates a Nix derivation from a Ninja build file. - GitHub - awakesecurity/ninja2nix: A tool that generates a Nix derivation from a Ninja build file.
But it does not have commits since 2017
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### Author:  [@Ericson2314](https://discourse.nixos.org/u/Ericson2314)
#### Post date: [May 31, 2020, 2:14pm UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/5 "2020-05-31T14:14:58Z")
That is largely because the it was being used for a specific project for Haskell that ran into other difficulties. The idea is still perfectly valid.
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### Author:  [@alst2821](https://discourse.nixos.org/u/alst2821)
#### Post date: [May 31, 2020, 10:23pm UTC](https://discourse.nixos.org/t/merkle-trees-and-build-systems-lwn-net/7429/6 "2020-05-31T22:23:37Z")
Thanks for the link. It bypasses the lwn subscription blocks - I would have had to wait a week to read it.