fix(deps): add Cross.toml to install libudev-dev for linux cross-compilation by jdx · Pull Request #326 · jdx/fnox

jdx · 2026-03-08T00:30:42Z

Summary

Adds Cross.toml with pre-build commands to install libudev-dev in Docker containers used by cross for Linux targets
Fixes build failures for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu caused by missing libudev (required by hidapi crate)
Uses $CROSS_DEB_ARCH for aarch64 to install the correct architecture's package

Test plan

cross build --target x86_64-unknown-linux-gnu succeeds locally
cross build --target aarch64-unknown-linux-gnu building locally
CI release workflow passes for both Linux targets

🤖 Generated with Claude Code

Note

Low Risk
Build-only configuration change that affects cross-compilation container setup, with minimal impact on runtime behavior.

Overview
Adds a new Cross.toml to customize cross Docker images for Linux builds by running pre-build apt commands.

The pre-build steps install libudev-dev for x86_64-unknown-linux-gnu, and for aarch64-unknown-linux-gnu they add the appropriate Debian architecture and install the arch-specific libudev-dev package via $CROSS_DEB_ARCH.

^{Written by Cursor Bugbot for commit cca6388. This will update automatically on new commits. Configure here.}

…ilation The hidapi crate requires libudev-dev at build time. When using cross for Linux targets, the default Docker images don't have it installed. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gemini-code-assist · 2026-03-08T00:30:52Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses critical build failures during cross-compilation for Linux targets by adding a Cross.toml configuration. This new file specifies pre-build commands to install the libudev-dev package, which is a necessary dependency for the hidapi crate, ensuring successful builds for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu environments.

Highlights

Cross-compilation configuration: Introduced a Cross.toml file to define pre-build steps for Linux cross-compilation targets.
Dependency resolution: Ensured libudev-dev is installed in Docker containers used by cross to resolve build failures caused by missing libudev for hidapi crate.
Architecture-specific installation: Utilized $CROSS_DEB_ARCH for aarch64 targets to correctly install the architecture-specific libudev-dev package.

Changelog

Cross.toml
- Added pre-build commands to install libudev-dev for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu targets.

Activity

The pull request was generated using Claude Code.
The author has provided a test plan, including local verification for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu builds, and a check for the CI release workflow.

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Code Review

This pull request adds a Cross.toml file to fix cross-compilation for Linux by installing libudev-dev. The approach is correct. My review includes suggestions to improve the pre-build commands by following containerization best practices, such as chaining apt-get commands and cleaning up the cache to reduce image size and improve robustness.

_{Note: Security Review has been skipped due to the limited scope of the PR.}

gemini-code-assist · 2026-03-08T00:31:40Z

+    "apt-get update",
+    "apt-get install -y libudev-dev",


For better robustness and smaller container image sizes, it's a good practice to chain apt-get commands, use --no-install-recommends, and clean up the cache afterwards. This ensures atomicity and prevents installing unnecessary packages.

"apt-get update && apt-get install -y --no-install-recommends libudev-dev && rm -rf /var/lib/apt/lists/*"

gemini-code-assist · 2026-03-08T00:31:40Z

+    "apt-get update",
+    "apt-get install -y libudev-dev:$CROSS_DEB_ARCH",


Similar to the other target, it's a good practice to chain apt-get commands, use --no-install-recommends, and clean up the cache to create smaller and more robust container images.

"apt-get update && apt-get install -y --no-install-recommends libudev-dev:$CROSS_DEB_ARCH && rm -rf /var/lib/apt/lists/*"

greptile-apps · 2026-03-08T00:32:21Z

Greptile Summary

This PR adds a Cross.toml configuration file to fix Linux cross-compilation builds by installing libudev-dev as a pre-build step inside the cross Docker containers. The dependency is required by the hidapi crate (pulled in transitively via ctap-hid-fido2), which links against libudev on Linux.

Adds Cross.toml with pre-build commands for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu targets
Correctly uses dpkg --add-architecture $CROSS_DEB_ARCH + libudev-dev:$CROSS_DEB_ARCH for the aarch64 target to install the ARM64 variant of the package into the x86_64 cross-compilation container
Directly corresponds to the two Linux targets using cross in .github/workflows/release.yml
Note: the aarch64 build is not yet verified locally (marked unchecked in the test plan)

Confidence Score: 4/5

Safe to merge — the change is a single, well-scoped config file that follows the documented cross pattern for adding system dependencies.
The approach is correct: $CROSS_DEB_ARCH is the proper environment variable provided by cross for target Debian architecture names, and the two-step dpkg --add-architecture + arch-suffixed install is the standard pattern for cross-arch packages. The only open question is the untested aarch64 path (unchecked in the test plan), which is a minor risk but not a code correctness issue.
No files require special attention.

Important Files Changed

Filename	Overview
Cross.toml	New file configuring `cross` pre-build commands to install `libudev-dev` for both Linux targets; uses correct `$CROSS_DEB_ARCH` pattern for aarch64 cross-architecture package installation.

Sequence Diagram

sequenceDiagram
    participant GH as GitHub Actions
    participant Cross as cross (build tool)
    participant Docker as Cross Docker Container
    participant Cargo as cargo build

    GH->>Cross: cross build --target <linux-target>
    Cross->>Docker: Start container for target
    Docker->>Docker: Execute pre-build commands (Cross.toml)
    Note over Docker: apt-get update
    Note over Docker: [aarch64] dpkg --add-architecture $CROSS_DEB_ARCH
    Note over Docker: apt-get install -y libudev-dev[:<arch>]
    Docker->>Cargo: Build fnox (with libudev available)
    Note over Cargo: ctap-hid-fido2 → hidapi → libudev-dev resolved
    Cargo-->>GH: Binary artifact

_{Last reviewed commit: cca6388}

@jdx

### 🐛 Bug Fixes - **(set)** error on encryption failure; use LocalStack for AWS tests by [@jdx](https://github.com/jdx) in [#324](#324) ### 📦️ Dependency Updates - add Cross.toml to install libudev-dev for linux cross-compilation by [@jdx](https://github.com/jdx) in [#326](#326)

fix(deps): add Cross.toml to install libudev-dev for linux cross-comp…

cca6388

…ilation The hidapi crate requires libudev-dev at build time. When using cross for Linux targets, the default Docker images don't have it installed. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gemini-code-assist Bot reviewed Mar 8, 2026

View reviewed changes

jdx enabled auto-merge (squash) March 8, 2026 00:32

jdx merged commit f1a794e into main Mar 8, 2026
21 checks passed

jdx deleted the fix/cross-libudev branch March 8, 2026 00:50

mise-en-dev mentioned this pull request Mar 8, 2026

chore: release v1.16.1 #325

Merged

BrewTestBot mentioned this pull request Mar 8, 2026

fnox 1.16.1 Homebrew/homebrew-core#271171

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fix(deps): add Cross.toml to install libudev-dev for linux cross-compilation#326

fix(deps): add Cross.toml to install libudev-dev for linux cross-compilation#326
jdx merged 1 commit intomainfrom
fix/cross-libudev

jdx commented Mar 8, 2026 •

edited

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		"apt-get update",
		"apt-get install -y libudev-dev:$CROSS_DEB_ARCH",

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jdx commented Mar 8, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary of Changes

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greptile-apps Bot commented Mar 8, 2026

Greptile Summary

Confidence Score: 4/5

Important Files Changed

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jdx commented Mar 8, 2026 •

edited

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