rust

@icorbrey

Load this skill for non-trivial work in a Cargo workspace. Covers what is genuinely peculiar to Cargo as an agent encounters it — keeping the build cache from exploding into tens of gigabytes, the workspace-deps feature-flag transit gotcha, and the architectural rule for keeping CLI-bearing crates testable. The general engineering-discipline rules (oracles, testing domains, evidence) live in `rigor`; the commit-shaping rules live in `jujutsu`.