#assistant #upgrade #move #snafu

app snafu-upgrade-assistant

Helps upgrade SNAFU between semver-incompatible versions

1 stable release

1.0.0 Jan 4, 2022


341 lines


Upgrades usages of SNAFU 0.6 to 0.7.


  1. Install the assistant

    cargo install snafu-upgrade-assistant
  2. Run the assistant inside of your Cargo project


    This should compile successfully and make no changes to your files.

  3. Update SNAFU from 0.6 to 0.7 in your Cargo.toml

  4. Run the assistant again

  5. Commit changes and run tests

What's going on?

In SNAFU 0.7, generated context selectors now have the Snafu suffix to help de-mystify the generated code. This tool builds your code, looks at the compiler error messages, and applies automated transformations to try to get it building again.

What options exist?

Run the assistant with --help for the complete list of options. Some commonly used ones are:

  • --dry-run. When set, the assistant will do one iteration of fixes and print out what files would be modified.

  • --extra-check-arg. When provided, the assistant will use these extra arguments to cargo check. Can be used more than once. Useful for passing feature flags (--extra-check-arg --feature=cool-thing) or workspace related configuration (--extra-check-arg --all).

Is this safe?

The assistant is designed to only change files inside of the current working directory that the Rust compiler reports errors have occurred in. That said, you should always start work with a clean version control state, and it doesn't hurt to have a backup of your directory.


~76K SLoC