commercialhaskell/stack

Nix integration should use GC roots

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#3,479 opened on Oct 9, 2017

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 (8 comments) (9 reactions) (0 assignees)Haskell (4,060 stars) (848 forks)batch import
component: nixhelp wanted

Description

Usual scenario:

  1. build stack project with Nix
  2. sometime later you run nix-store --gc or nix-collect-garbage
  3. you run into following error:
/home/user/.stack/setup-exe-cache/x86_64-linux-nix/Cabal-simple_mPHDZzAJ_1.24.2.0_ghc-8.0.2: streamingProcess: runInteractiveProcess: exec: does not exist (No such file or directory)

This means that nix libraries that the file was compiled with are missing from nix store.

Best way to prevent this is to create Nix GC roots. Also stack could double check that those libraries are still intact.

Contributor guide

Tech stack
None
Domain
build systemcli
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Nix package managerHaskell build tool stack
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue requests creating Nix GC roots to prevent garbage collection from breaking built executables. Investigate how stack currently compiles with Nix and where to add root registration (likely in the Nix integration code). Check if any existing PRs or discussions address this. A concrete implementation would involve finding the Nix store paths used and registering them as GC roots, possibly using `nix store add root`. Also verify that stack can double check the integrity of those libraries.