Hoisted installs re-import patched packages and every package peering on one #17188

Verify latest release

• I verified that the issue exists in the latest pnpm release

pnpm version

12.14.0. Also reproduces on main at 1332461.

Link to the code that reproduces this issue or a replay of the bug

https://github.com/arthur-fontaine/pnpm-hoisted-patched-peers-repro

Reproduction steps

git clone https://github.com/arthur-fontaine/pnpm-hoisted-patched-peers-repro
cd pnpm-hoisted-patched-peers-repro
./repro.sh

The project has nodeLinker: hoisted, a patched react, and react-dom, which peers on react. The script installs it, then runs pnpm add is-number@7.0.0 and checks whether node_modules/react and node_modules/react-dom are still the same directories.

Describe the Bug

pnpm add is-number prints Packages: +3 and imports react and react-dom again:

Packages: +3
FAIL: node_modules/react was imported again
FAIL: node_modules/react-dom was imported again

Any install that reaches the hoisted linker does the same: a patched package already in place is imported again, and so is every package whose peers include a patched package. react-dom@19.2.0(react@19.2.0(patch_hash=…)) is not patched, but its dep path carries the peer's patch_hash.

package_is_reusable in pnpm/crates/deps-restorer/src/hoisted_dep_graph/walk.rs excludes any reference that contains (patch_hash=.

Without patchedDependencies, 12.14.0 prints Packages: +1.

In a React Native workspace with patched react-native and expo, each such install imports 115 packages again and takes 27.6s. Leaving them in place brings it to 9–11s.

Expected Behavior

Packages: +1, with react and react-dom left in place, as pnpm 10 and 11 do.

Which Node.js version are you using?

24.16.0

Which operating systems have you used?

• macOS
• Windows
• Linux

Contributing a fix

• I am working on a fix

Written by an agent (Claude Code, claude-opus-5-5).