fix(env): drop stale mise install dirs from mise x/run child PATH

[JamBalaya56562]

What

mise x tool@X / run / env correctly remap the direct command, but a stale mise-managed install dir left earlier on PATH — e.g. carried in from a frozen env snapshot of a previously activated shell (IDE terminals, CI wrappers, AI-agent harnesses) — stayed ahead of the bin dir mise injects. So PATH lookups inside the process tree (subshells, #!/usr/bin/env shebangs, package managers spawning workers) still resolved the other version: a split-brain where node --version says 22 while the tests actually run on 24.

Reported in #10345 (repro with two node versions).

Fix

When Toolset composes the child environment, filter mise-managed install dirs out of the inherited PATH (mise re-adds the current toolset's bin dirs, so the requested version wins for the whole process tree). Mirrors the hook-env reactivation fix (#10162): its is_mise_install_path helper is moved to path_env, shared, and extended to also cover shared/system install dirs (MISE_SHARED_INSTALL_DIRS + the system installs dir) that find_in_shared_installs resolves into. The install-dir list is computed once per PATH-composition pass to keep the per-entry check cheap (hook-env runs on every prompt).

Tests

• e2e/cli/test_exec_stale_install_path: with installs/dummy/2.0.0/bin prepended to PATH, mise x dummy@1.0.0 -- sh -c 'command -v dummy' resolves into installs/dummy/1.0.0, not the stale 2.0.0 dir.

Addresses discussion #10345.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Fixed version resolution when stale mise-managed install directories are left on PATH, ensuring mise x selects the requested version instead of being influenced by older remnants.
  • Updated PATH handling to exclude mise-managed install directory entries when building the effective environment, preventing incorrect PATH ordering.

• Tests

  • Added an end-to-end regression test covering stale install-path behavior and verifying correct resolution in both direct and child-process commands.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: f08f45e6-cfb3-49c4-bdfe-bd1c669af9bb

📥 Commits

Reviewing files that changed from the base of the PR and between 1b2bcd8 and c9a30a5.

📒 Files selected for processing (4)

• e2e/cli/test_exec_stale_install_path
• src/cli/hook_env.rs
• src/path_env.rs
• src/toolset/toolset_env.rs

🚧 Files skipped from review as they are similar to previous changes (4)

• e2e/cli/test_exec_stale_install_path
• src/path_env.rs
• src/cli/hook_env.rs
• src/toolset/toolset_env.rs

---

📝 Walkthrough

Walkthrough

Centralizes install-path detection into path_env.rs, filters stale install dirs from env::PATH across all PATH construction sites in toolset_env.rs, refactors hook_env.rs to use shared helpers, and adds a regression test validating the fix.

Changes

Stale install dir PATH fix

Layer / File(s)	Summary
Centralized install-dir detection helpers src/path_env.rs	Adds mise_install_dirs() returning all mise-managed install directories and is_mise_install_path() classifying a path via prefix matching with canonicalization fallback.
hook_env.rs refactored to shared helpers src/cli/hook_env.rs	Removes the local is_mise_install_path helper, cleans up imports, and updates build_path_operations to precompute mise_install_dirs once and delegate to crate::path_env.
Stale dirs filtered at all PATH construction sites src/toolset/toolset_env.rs	Adds pristine_path_without_install_dirs() that strips mise install dir entries from env::PATH; substitutes it for raw env::PATH in env_with_path_without_tools, env_with_path, env_with_path_and_split, try_load_env_cache, and final_env.
E2E regression test e2e/cli/test_exec_stale_install_path	New bash test simulating a frozen-shell stale-PATH scenario, asserting mise x dummy@1.0.0 resolves to 1.0.0 both directly and in a spawned child process.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• jdx/mise#10162: Addresses the same stale-entry detection logic in src/cli/hook_env.rs for PATH ordering; this PR directly builds on that work by extracting that detection into src/path_env.rs and applying it to toolset_env.rs.

Poem

🐇 Hoppity-hop down the PATH I go,
Old stale bins piled high like snow.
But now I sweep with pristine_path,
No ghost of 2.0.0 blocks my math.
The right dummy answers my call —
1.0.0 wins, stale dirs fall! 🎉

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: filtering stale mise install directories from the PATH in mise x/run child processes to ensure correct tool version resolution.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[greptile-apps]

Greptile Summary

This PR fixes a split-brain version resolution issue where a stale mise-managed install dir carried in via a frozen env snapshot (IDE terminal, CI wrapper) stayed ahead of the bin dir mise x/run/env injects, causing subshells and shebangs inside the process tree to see the wrong version.

• Core fix: Introduces pristine_path_without_install_dirs() in toolset_env.rs that strips all mise-managed install dirs (primary + shared/system) from the inherited PATH before the current toolset's bin dirs are prepended. All six PATH-building sites are updated consistently.
• Shared helper: is_mise_install_path is moved from hook_env.rs into path_env.rs and extended to also cover MISE_SHARED_INSTALL_DIRS and the system installs dir.
• Regression test: e2e/cli/test_exec_stale_install_path prepends the 2.0.0 bin dir to PATH and asserts that command -v dummy inside a child shell resolves to the 1.0.0 install dir.

Confidence Score: 5/5

Safe to merge — the change is narrowly scoped to filtering mise-managed dirs before PATH construction and all existing PATH-building paths are updated consistently.

Every PATH-building site in toolset_env.rs (cached and non-cached) now strips stale install dirs before adding the current toolset bins. The shared helper is a clean extraction with broader coverage, and the regression test directly exercises the broken child-process PATH lookup.

No files require special attention.

Important Files Changed

Filename	Overview
src/path_env.rs	Adds mise_install_dirs() and is_mise_install_path() helpers, refactored out of hook_env.rs and extended to cover shared/system install dirs. Logic is correct: literal prefix check first, then canonicalized fallback.
src/toolset/toolset_env.rs	All six PATH-building sites (cached and non-cached paths) are updated to start from pristine_path_without_install_dirs(), ensuring stale install dirs are stripped before the current toolset's bins are re-added.
src/cli/hook_env.rs	Removes the private is_mise_install_path and delegates to the new shared helper in path_env, passing the pre-computed mise_install_dirs list.
e2e/cli/test_exec_stale_install_path	New regression test prepends a stale 2.0.0 bin dir to PATH, then asserts both the direct command and a command -v inside a child shell resolve to 1.0.0.

_{Reviews (2): Last reviewed commit: "fix(env): drop stale mise install dirs f..." | Re-trigger Greptile}