Producing a Minimal, Reproducible Example (MRE) for Rust code

Questions on Stack Overflow that seek debugging help ("why isn't this code working?") must include the shortest code necessary to reproduce it in the question itself. Without it, the question is off-topic and is likely to be closed. Here are some common points to follow to reduce your code to create a good MRE:

• Try to run your code in a different environment.

  • On the Rust Playground
  • In a separate Cargo project

• If your code fails to compile, include a copy of the error message, preferably complete and unmodified from the compiler's output.

• Remove unused

  • crates
  • modules
  • types
  • enum variants / members
  • struct members
  • function arguments / return values

• Combine modules in multiple files into a single file by rewriting:

  mod foo;

  as

  mod foo { /* contents of foo.rs */ }

• Replace complete or partial statements or entire function bodies with the macro unimplemented!().

• Replace expressions and variables with hard-coded values. For example, replace a boolean value with true or false.

• Remove containing loops and conditional flow statements.

Remember that some steps might "unlock" other steps; try to apply each step in turn until no steps can be followed! Ensure that your error continues to occur after each change to avoid going down the wrong path.

There's also some information that you should provide about your code:

• It will be assumed that you are using the current stable version of Rust. If you are not using this version of Rust, state your version. This can be found by running rustc --version.

• If you are using crates, state the versions of every crate that you are using. This can be found in your Cargo.lock file.

Other locations

This document is also available on Stack Overflow as part of the Rust tag's information page.

License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.