develata/rust-auto-fixer

Rust Auto Fixer

Overview

This skill provides an automated loop for fixing Rust compilation errors. It takes a Rust code snippet, runs it through a real compiler (cargo check), analyzes the output, and iteratively applies fixes.

It is particularly useful for:

1. Validating code generated by the Agent.
2. Fixing tricky ownership and borrow checker errors (E0382, E0502).
3. Ensuring dependencies are correctly handled.

Workflow

1. Review Input: Analyze the provided code and context.
2. Check Code: Call check_rust_code.
   • This tool automatically attempts to detect dependencies based on use statements.
3. Analyze Results: 23→ - SUCCESS: If the tool returns "SUCCESS" followed by code, the code is valid. 24→ - IMPORTANT: The tool returns the rustfmt formatted code after "SUCCESS". 25→ - You MUST use this formatted code in your final <code_block>. 26→ - ERRORS: If errors are returned, analyze them using the strategies in Rust Fix Strategies. 27→4. Fix & Verify (Loop Constraint): 26→ - Apply the fix (e.g., adding .clone(), changing lifetimes, fixing types). 27→ - CRITICAL: You have a maximum budget of 3 attempts. 28→ - If the code still fails after 3 fixes, STOP and output the last error with a note: "Max attempts reached." 29→ - (Optional) Re-run check_rust_code to verify. 30→5. Output: Return the final result.

Tools

check_rust_code

Located at scripts/cargo_runner.py.

• Auto-Dependency Detection: Scans for use crate::module patterns and adds them to Cargo.toml with version *.
• JSON Output: Returns parsed compiler errors for easy analysis.
• Formatting: Automatically runs rustfmt on success and returns the formatted code.
• Caching: Uses a persistent build directory to speed up compilation.

Usage:

1. Save the Rust code snippet to a temporary file (e.g., temp.rs).
2. Run the python script with the file path as an argument:

   python scripts/cargo_runner.py temp.rs
   

3. Read the output. It will be "SUCCESS" or a list of error messages.

Input Schema

<input_schema>
  <code_snippet>
  // The Rust code.
  // Dependencies are auto-detected from 'use' statements.
  // For macros like #[macro_use] extern crate ..., detection might fail.
  // Note: For best results, please include use statements for external crates, or mention them in the context.
  </code_snippet>
  <context>Optional context</context>
</input_schema>

Output Schema

<fixed_result> 
  <original_errors>Summary of errors found</original_errors> 
  <explanation>Explanation of the fix applied</explanation> 
  <code_block>The fixed Rust code</code_block>
</fixed_result>