fix(rust): resolve relative CARGO_HOME/RUSTUP_HOME to absolute paths by simonepri · Pull Request #8604 · jdx/mise

simonepri · 2026-03-15T10:45:35Z

Problem

When CARGO_HOME or RUSTUP_HOME is set to a relative path (e.g. .cargo via [env] in mise.toml), the rust plugin uses it as-is. This produces relative PATH entries like .cargo/bin that only work from the project directory. When mise hook-env persists these into the shell and the user changes directories, the relative paths break — surfacing as undefined/bin in PATH.

Solution

cargo_home() and rustup_home() now resolve relative paths to absolute using current_dir() before returning

Repro

# mise.toml
[tools]
rust = "stable"

[env]
CARGO_HOME = ".cargo"
RUSTUP_HOME = ".rustup"

mise env | tr ':' '\n' | grep cargo
# Before: .cargo/bin (relative → breaks after cd, becomes undefined/bin)
# After:  /absolute/path/to/project/.cargo/bin

gemini-code-assist · 2026-03-15T10:45:46Z

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 resolves an issue where relative CARGO_HOME or RUSTUP_HOME paths, when configured and persisted in the shell environment, would become invalid upon changing directories. By ensuring these paths are consistently resolved to absolute paths, the system can reliably locate Rust-related binaries and tools, preventing errors like undefined/bin regardless of the current working directory.

Highlights

Path Resolution: Modified the rustup_home() and cargo_home() functions to resolve relative paths specified by RUSTUP_HOME or CARGO_HOME environment variables (or mise.toml settings) into absolute paths using the current working directory.

Changelog

src/plugins/core/rust.rs
- Updated rustup_home function to convert relative RUSTUP_HOME paths to absolute paths.
- Updated cargo_home function to convert relative CARGO_HOME paths to absolute paths.

Activity

No human activity has been recorded for this pull request yet.

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Code Review

This pull request correctly addresses an issue where relative paths for CARGO_HOME or RUSTUP_HOME could cause problems. The approach of resolving them to absolute paths is sound. My review includes suggestions to simplify the implementation in both rustup_home and cargo_home functions. These changes will improve code clarity and remove duplication.

greptile-apps · 2026-03-15T10:47:58Z

Greptile Summary

This PR fixes a real bug where relative CARGO_HOME / RUSTUP_HOME paths (set via [env] in mise.toml) were propagated as-is into PATH, causing them to break whenever the user changed directories. The fix is functionally correct: both rustup_home() and cargo_home() now resolve relative paths against current_dir(), and the is_relative() guard correctly avoids an unnecessary syscall for the common absolute-path case.

Two minor quality gaps are worth addressing before merge:

Duplicated resolution logic: The identical is_relative() + current_dir() block appears in both helpers. Extracting it into a small private resolve_path(path: PathBuf) -> PathBuf would reduce duplication and centralise any future changes.
Silent fallback on current_dir() failure: unwrap_or(path) silently re-introduces the broken relative-path behaviour if the working directory cannot be read. A warn! log at that point would give users an actionable diagnostic instead of the confusing undefined/bin symptom returning unexpectedly.

Confidence Score: 4/5

Safe to merge — the logic change is correct and well-scoped, with only minor style and observability improvements remaining.
The fix correctly addresses the described bug. The is_relative() guard prevents unnecessary syscalls for the common case. The only concerns are code duplication and a silent failure path in an edge case, neither of which affects correctness in normal usage.
src/plugins/core/rust.rs — review the duplicate resolution logic and the silent current_dir() fallback.

Important Files Changed

Filename	Overview
src/plugins/core/rust.rs	Adds relative-to-absolute path resolution in `rustup_home()` and `cargo_home()` using `current_dir()` guarded by `is_relative()`; logic is correct but duplicated across both helpers, and the silent fallback on `current_dir()` failure could mask errors.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["rustup_home() / cargo_home() called"] --> B["Read from Settings / env var"]
    B --> C{"Path found?"}
    C -- No --> D["Use default: dirs::HOME.join('.rustup|.cargo')"]
    C -- Yes --> E["Use configured path"]
    D --> F{"path.is_relative()?"}
    E --> F
    F -- No --> G["Return absolute path as-is"]
    F -- Yes --> H["Call std::env::current_dir()"]
    H --> I{"current_dir() succeeds?"}
    I -- Yes --> J["Return cwd.join(path)"]
    I -- No --> K["Silent fallback: return relative path unchanged\n⚠ still broken behaviour"]

_{Last reviewed commit: 29fcba9}

When CARGO_HOME or RUSTUP_HOME is set to a relative path (e.g. ".cargo" via [env] in mise.toml), the rust plugin used it as-is, producing relative PATH entries like ".cargo/bin". After mise hook-env persists these into the shell and the user changes directories, the relative paths break — surfacing as "undefined/bin" in PATH. Resolve relative paths to absolute via current_dir() in cargo_home() and rustup_home() before returning. Co-Authored-By: Claude Opus 4.6 <[email protected]>

greptile-apps · 2026-03-15T13:37:01Z

+    if path.is_relative() {
+        std::env::current_dir()
+            .map(|cwd| cwd.join(&path))
+            .unwrap_or(path)
+    } else {
+        path
+    }


Silent fallback to relative path on current_dir() failure

When std::env::current_dir() fails (e.g. the working directory has been deleted, or the process lacks read permission on it), unwrap_or(path) silently falls back to returning the original relative path — which is exactly the broken behaviour this PR is fixing. Users would see the same undefined/bin symptom with no indication of why.

Consider emitting a warn! log so that users (and bug reports) have an actionable signal:

Suggested change

if path.is_relative() {

std::env::current_dir()

.map(|cwd| cwd.join(&path))

.unwrap_or(path)

} else {

path

}

if path.is_relative() {

match std::env::current_dir() {

Ok(cwd) => cwd.join(&path),

Err(e) => {

warn!("could not determine current directory to resolve relative path {:?}: {e}", path);

path

}

}

} else {

path

}

The same applies to cargo_home() at lines 384–390.

@tdragon

### 🐛 Bug Fixes - **(config)** resolve trust hash collision for same-name directories by @tdragon in [#8628](#8628) - **(docs)** fix width of tools table by @himkt in [#8625](#8625) - **(docs)** prevent homepage hero atmosphere overflow by @nygmaaa in [#8642](#8642) - **(doctor)** detect PATH ordering issues when mise is activated by @jdx in [#8585](#8585) - **(git)** use origin as remote name by @bentinata in [#8626](#8626) - **(installer)** normalize current version before comparison by @tak848 in [#8649](#8649) - **(lockfile)** Resolve symlink when updating lockfiles by @chancez in [#8589](#8589) - **(python)** verify checksums for precompiled binary downloads by @malept in [#8593](#8593) - **(rust)** resolve relative CARGO_HOME/RUSTUP_HOME to absolute paths by @simonepri in [#8604](#8604) - **(task)** correctly resolve task name for _default files with extensions by @youta1119 in [#8646](#8646) - **(tasks)** global file tasks not properly marked as such by @roele in [#8618](#8618) - **(tasks)** handle broken pipe in table print and task completion output by @vmaleze in [#8608](#8608) - use dark/light logo variants in README for GitHub dark mode by @jdx in [#8656](#8656) - failing rebuild of runtime symlinks for shared tools by @roele in [#8647](#8647) - add spaces around current element operator in flutter version_expr by @roele in [#8616](#8616) - complete task arguments correctly by @KevSlashNull in [#8601](#8601) ### 📚 Documentation - switch body font to DM Sans and darken dark mode background by @jdx in [6e3ad34](6e3ad34) - use Cormorant Garamond for headers and Roc Grotesk for body text by @jdx in [010812a](010812a) - resolve chaotic heading hierarchy in task-arguments.md by @muzimuzhi in [#8644](#8644) ### 🧪 Testing - fix test_java and mark as slow by @roele in [#8634](#8634) ### 📦️ Dependency Updates - update docker/dockerfile:1 docker digest to 4a43a54 by @renovate[bot] in [#8657](#8657) - update ghcr.io/jdx/mise:alpine docker digest to 2584470 by @renovate[bot] in [#8658](#8658) ### 📦 Registry - add viteplus (npm:vite-plus) by @risu729 in [#8594](#8594) - remove backend.options for podman by @roele in [#8633](#8633) - add pi.dev coding agent by @dector in [#8635](#8635) - add ormolu ([github:tweag/ormolu](https://github.com/tweag/ormolu)) by @3w36zj6 in [#8617](#8617) - use version_expr for dart and sort versions by @roele in [#8631](#8631) ### New Contributors - @bentinata made their first contribution in [#8626](#8626) - @tdragon made their first contribution in [#8628](#8628) - @nygmaaa made their first contribution in [#8642](#8642) - @youta1119 made their first contribution in [#8646](#8646) - @chancez made their first contribution in [#8589](#8589) - @dector made their first contribution in [#8635](#8635) - @tak848 made their first contribution in [#8649](#8649) ## 📦 Aqua Registry Updates #### New Packages (5) - [`acsandmann/rift`](https://github.com/acsandmann/rift) - [`alltuner/mise-completions-sync`](https://github.com/alltuner/mise-completions-sync) - [`berbicanes/apiark`](https://github.com/berbicanes/apiark) - [`gitlab.com/graphviz/graphviz`](https://github.com/gitlab.com/graphviz/graphviz) - [`jorgelbg/pinentry-touchid`](https://github.com/jorgelbg/pinentry-touchid) #### Updated Packages (7) - [`UpCloudLtd/upcloud-cli`](https://github.com/UpCloudLtd/upcloud-cli) - [`aquaproj/registry-tool`](https://github.com/aquaproj/registry-tool) - [`go-swagger/go-swagger`](https://github.com/go-swagger/go-swagger) - [`gopinath-langote/1build`](https://github.com/gopinath-langote/1build) - [`sassman/t-rec-rs`](https://github.com/sassman/t-rec-rs) - [`sharkdp/fd`](https://github.com/sharkdp/fd) - [`temporalio/cli`](https://github.com/temporalio/cli)

gemini-code-assist Bot reviewed Mar 15, 2026

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Comment thread src/plugins/core/rust.rs

Comment thread src/plugins/core/rust.rs

simonepri force-pushed the fix/rust-relative-cargo-home-path branch from de52d75 to 683762d Compare March 15, 2026 13:08

greptile-apps Bot reviewed Mar 15, 2026

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Comment thread src/plugins/core/rust.rs Outdated

Comment thread src/plugins/core/rust.rs

simonepri force-pushed the fix/rust-relative-cargo-home-path branch from 683762d to 29fcba9 Compare March 15, 2026 13:35

greptile-apps Bot reviewed Mar 15, 2026

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jdx merged commit 642c004 into jdx:main Mar 19, 2026
34 checks passed

mise-en-dev mentioned this pull request Mar 19, 2026

chore: release 2026.3.10 #8592

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mise-en-dev mentioned this pull request Mar 21, 2026

chore: release 2026.3.11 #8676

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BrewTestBot mentioned this pull request Mar 21, 2026

mise 2026.3.10 Homebrew/homebrew-core#273539

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fix(rust): resolve relative CARGO_HOME/RUSTUP_HOME to absolute paths#8604

fix(rust): resolve relative CARGO_HOME/RUSTUP_HOME to absolute paths#8604
jdx merged 1 commit intojdx:mainfrom
simonepri:fix/rust-relative-cargo-home-path

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simonepri commented Mar 15, 2026

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Confidence Score: 4/5

Important Files Changed

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