feat: add flake.nix for Linux development and Nix packaging by Flexksx · Pull Request #2561 · moonrepo/moon

Flexksx · 2026-06-09T08:23:53Z

Summary

Adds flake.nix exposing packages.default (the moon + moonx binaries) and devShells.default for Linux development
Targets x86_64-linux and aarch64-linux
Pins the exact Rust 1.96.0 toolchain via rust-overlay reading rust-toolchain.toml
Adds .github/workflows/nix.yml as a guardrail — runs nix flake check and nix build on every relevant change

Motivation

The nixpkgs derivation for moon is currently at 1.41.8, while the project is at 2.3.2. A flake shipped with the repo lets Nix users pin directly to any commit or release without waiting for a nixpkgs update:

```bash
nix run github:moonrepo/moon -- --version

nix develop github:moonrepo/moon
```

Technical notes

OPENSSL_NO_VENDOR = 1 — reqwest enables native-tls-vendored for musl targets. On glibc Linux this forces pkg-config lookup of the system openssl instead of compiling it from source.

protobuf in nativeBuildInputs — crates/daemon-proto/build.rs invokes protoc via tonic-prost-build at compile time. This dependency was added after the nixpkgs derivation was last updated.

cargoLock.lockFile — the project has no git-sourced Cargo dependencies, so no outputHashes are needed.

doCheck = false — tests download Node, Bun, Deno, etc. at runtime and cannot pass in the Nix sandbox.

Test plan

nix flake check --no-build passes locally
Derivation evaluates to a valid .drv on x86_64-linux
nix build .#default succeeds in CI (workflow added in this PR)

Adds a Nix flake that provides: - packages.default: moon binary built with rustPlatform.buildRustPackage, pinned to the exact Rust 1.96.0 toolchain via rust-overlay. - devShells.default: full dev environment (rustToolchain, protobuf, openssl, just, cargo-nextest) matching what CI uses. Targets x86_64-linux and aarch64-linux. OPENSSL_NO_VENDOR=1 is set to avoid compiling vendored OpenSSL — reqwest's native-tls-vendored feature is present for musl targets only; on glibc Linux we rely on system openssl via pkg-config. protobuf is added to nativeBuildInputs because crates/daemon-proto/build.rs invokes protoc via tonic-prost-build at compile time. Also adds .github/workflows/nix.yml to keep the flake buildable on every relevant change. Closes: helps close the version gap between nixpkgs (1.35.5) and the current release (2.3.2). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Copilot

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds Nix Flake-based packaging/dev shell and a GitHub Actions workflow to validate the flake and build the default package in CI.

Changes:

Introduce flake.nix to build the Rust CLI via buildRustPackage and provide a dev shell.
Add GitHub Actions workflow to run nix flake check and nix build on relevant changes.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 4 comments.

File	Description
flake.nix	Defines flake inputs/outputs: Rust package build + devShell with Rust toolchain and native deps.
.github/workflows/nix.yml	Adds CI job to check the flake and build the default package on PRs/pushes.

- Remove all comments - Add installShellFiles + postInstall for bash/fish/zsh completions - Add writableTmpDirAsHomeHook (moon accesses HOME during postInstall) - Add RUSTFLAGS="-C strip=symbols" to match nixpkgs build flags - Drop cargoBuildFlags; default-members in Cargo.toml already scopes to moon_cli - Set doCheck = false; tests require internet and tool installation - Mirror env block style from nixpkgs package.nix Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

magic-nix-cache-action requires FlakeHub registration. Use plain actions/cache on /nix/store keyed on flake.lock + Cargo.lock instead. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Copilot

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 3 comments.

+          env = {
+            RUSTFLAGS = "-C strip=symbols";
+            OPENSSL_NO_VENDOR = 1;
+          };


+        }).buildRustPackage {
+          pname = "moon";
+          version = "2.3.2";
+          src = ./.;
+
+          cargoLock.lockFile = ./Cargo.lock;
+


+      - uses: actions/cache@v4
+        with:
+          path: /nix/store
+          key: nix-${{ runner.os }}-${{ hashFiles('flake.lock', 'Cargo.lock') }}
+          restore-keys: nix-${{ runner.os }}-


milesj · 2026-06-13T16:13:02Z

@Flexksx I'm not familiar with nix, what does this do exactly? Allow people to use moon in their nix environment?

Flexksx · 2026-06-14T13:00:24Z

@milesj hi!

Allow people to use moon in their nix environment?

Yes, that's the biggest reason

Nix lets you package packages in a way that keeps them isolated, so I could have 2 different projects using moon and I could configure them to use slightly different versions of moon.

And each project would have its own isolated moon that is provided through the nix store.

I just recently stumbled across moon and I'm using it for a personal project and to be fair I'm amazed at how old is the current nixpkgs version for it, so I opened a PR as well NixOS/nixpkgs#529832

So for my project, I had to configure nix in a way that would build it from a specific, newer commit in the repo.
Which does not really have that much ergonomics 🤷

So adding a flake.nix would let as well other people easier interact with it, install it on their machines.

Also having a flake.nix lets other people with nix systems develop and contribute safely, since normally on NixOS you don't really install any packages globally, everything is managed with nix

codspeed-hq · 2026-06-14T14:13:52Z

Merging this PR will not alter performance

⚠️

Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

✅ 23 untouched benchmarks

_{Comparing Flexksx:feat/nix-flake (285c3e6) with master (b009ad3)}

Copilot AI review requested due to automatic review settings June 9, 2026 08:23

Copilot AI reviewed Jun 9, 2026

View reviewed changes

Comment thread flake.nix

Comment thread .github/workflows/nix.yml

Comment thread flake.nix Outdated

Comment thread flake.nix Outdated

Flexksx and others added 3 commits June 9, 2026 11:26

ci(nix): trigger on feat/nix-flake and add workflow_dispatch

a1174b9

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ci(nix): replace magic-nix-cache with actions/cache

9cddf41

magic-nix-cache-action requires FlakeHub registration. Use plain actions/cache on /nix/store keyed on flake.lock + Cargo.lock instead. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Flexksx requested a review from Copilot June 9, 2026 11:08

Copilot AI reviewed Jun 9, 2026

View reviewed changes

Merge branch 'master' into feat/nix-flake

285c3e6

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

feat: add flake.nix for Linux development and Nix packaging#2561

feat: add flake.nix for Linux development and Nix packaging#2561
Flexksx wants to merge 5 commits into
moonrepo:masterfrom
Flexksx:feat/nix-flake

Flexksx commented Jun 9, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

milesj commented Jun 13, 2026

Uh oh!

Flexksx commented Jun 14, 2026

Uh oh!

codspeed-hq Bot commented Jun 14, 2026

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

Uh oh!

Conversation

Flexksx commented Jun 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Motivation

Technical notes

Test plan

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

milesj commented Jun 13, 2026

Uh oh!

Flexksx commented Jun 14, 2026

Uh oh!

codspeed-hq Bot commented Jun 14, 2026

Merging this PR will not alter performance

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

Flexksx commented Jun 9, 2026 •

edited

Loading