# pnpm 12.0: Package Manager Rewritten in Rust

Faster, more secure, and more consistent dependency management

- **Source:** [Hacker News: Front Page](https://brifing.si/source/b07aa772-b1a0-4a76-aa18-719c6f9e2dde)
- **Published:** 2026-08-27
- **Topic:** [Software & Engineering](https://brifing.si/c/engineering)
- **Original article:** <https://pnpm.io/blog/releases/12.0>
- **On Brifing:** https://brifing.si/s/257aeee6-1568-427f-a1a4-0db49fe7135b

## Rewritten in Rust

pnpm 12.0 is a complete rewrite of the original JavaScript codebase in Rust. This transition brings performance improvements and lower memory usage. All pnpm 11 commands, flags, and settings remain compatible. Rust's thread safety and deep optimizations make a noticeable difference, especially in large projects.

## Git Dependency Changes

pnpm 12 changes how GitHub, GitLab, and Bitbucket dependencies are handled. It now uses HTTPS URLs by default instead of SSH, and lockfiles no longer store SSH URLs. For private repositories, Git's URL rewriting feature can be configured. This change improves security while making dependency resolution more consistent.

## Unrecognized Settings Now Reported

Previous versions silently ignored misspelled settings. pnpm 12 detects unrecognized settings and suggests similar valid options. If a project pins a specific pnpm version, unrecognized settings cause the command to fail. This makes configuration errors easier to catch early in the development process.

## Improved Dependency Cycle Handling

pnpm 12 breaks dependency cycles more consistently. Cycle members are ordered by package ID, and cuts always occur at the same points. This makes the lockfile a pure function of the dependency graph. As a result, peer resolution is 2-3x faster in large projects, uses 25% less memory, and produces smaller lockfiles.

## Filesystem Optimizations

On Linux, pnpm 12 now tries hardlinks first when creating node_modules, falling back to clones if needed. This cuts installation time in half on btrfs. macOS continues using APFS clonefile. ext4 behavior remains unchanged as cloning was never supported there. These optimizations significantly improve installation speed.

## Stricter Engine Compatibility

In engineStrict mode, pnpm 12 now fails when encountering incompatible packages in the regular dependency tree. pnpm 11 only emitted warnings in this case. Packages reachable only through optional dependencies are still skipped. This change makes project compatibility more reliable and predictable.

## Global Shim Feature

pnpm 12 introduces project-aware version management for globally installed node, deno, and bun. The globalShims setting controls which global packages get this treatment. By default, node, deno, and bun are enabled. For untrusted projects, execution requires confirmation, and responses are remembered machine-wide.

## Expanded Package Manager Support

pnpm 12 adds automatic installation support for npm, Yarn Classic, Yarn Berry, Yarn 6, and Bun. These package managers are fetched from trusted sources and verified before execution. Git dependencies can be prepared with their requested package manager. The pnx command runs one-off commands, and pnpm shim add creates project-specific manager links.

## What pnpm 12 Brings

pnpm 12 delivers significant performance gains through its Rust rewrite. Dependency resolution becomes more consistent while security measures are strengthened. Large projects see noticeable speed improvements and memory efficiency. The expanded package manager ecosystem support offers developers a more flexible working environment.

## Sources covering this story

- https://pnpm.io/blog/releases/12.0 — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._