Error index

Every diagnostic the Resilient compiler emits gets a stable code — E0001, E0002, etc. When you see one in your terminal or IDE, look it up here for a minimal reproducing example and the standard fix.

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Layout

Codes are grouped by the pipeline stage that can emit them:

• E0001..E0003 — parser
• E0004..E0006, E0015 — name resolution
• E0007, E0013, E0016, E0017 — type checker
• E0008, E0009, E0014, E0018 — runtime (interpreter / VM / JIT)
• E0010, E0019 — contracts (requires / ensures)
• E0011, E0012 — declarations / bindings
• E0020 — effects / purity
• E0021 — trait objects (dyn Trait)

Numbers are sticky: once assigned, a code is never reused. If a diagnostic is removed, its code is retired but the docs page stays as a redirect so external cheat sheets don’t silently break.

Status

RES-206a shipped the initial registry + docs pages for the first ten codes. RES-4115 (E-E4) extended the registry to E0011..E0021, added the rz explain E00NN / rz errors list CLI subcommands, migrated the high-traffic typechecker/parser/runtime call sites to emit their code behind RESILIENT_RICH_DIAG=1 (byte-identical output otherwise, so .expected.txt goldens stay pinned), and added two CI-enforced guards:

• docs_error_registry_generation_smoke.rs validates every page’s front matter (title, parent, nav_order, permalink) and heading against diag::codes, and checks this index links every registered code in registry order — so the registry and the docs site can’t silently drift apart.
• codeless_diagnostic_lint_smoke.rs fails the build if a new render_*_error funnel function (or Diagnostic::new call site outside diag.rs’s own tests) is added without a registered code, via a shrinking allowlist of the pre-existing legacy call sites that still return a bare, codeless String.

Browse

See the sidebar for the full list, or jump directly:

• E0001 — Generic parse error
• E0002 — Expected / missing ;
• E0003 — Unclosed delimiter
• E0004 — Unknown identifier
• E0005 — Unknown function
• E0006 — Call arity mismatch
• E0007 — Type mismatch
• E0008 — Division by zero
• E0009 — Array index out of bounds
• E0010 — Contract violation
• E0011 — Duplicate function definition
• E0012 — Reassignment of an immutable binding
• E0013 — Missing return on a code path
• E0014 — Unwrap of a None optional
• E0015 — Import target not found
• E0016 — Generic trait bound not satisfied
• E0017 — Unknown or missing struct field
• E0018 — Recursion / stack usage limit exceeded
• E0019 — Z3 could not prove a contract clause
• E0020 — Effect/purity violation
• E0021 — dyn Trait object-safety violation

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Table of contents

• E0001 — Generic parse error
• E0002 — Expected / missing `;`
• E0003 — Unclosed delimiter
• E0004 — Unknown identifier
• E0005 — Unknown function
• E0006 — Call arity mismatch
• E0007 — Type mismatch
• E0008 — Division by zero
• E0009 — Array index out of bounds
• E0010 — Contract violation
• E0011 — Duplicate function definition
• E0012 — Reassignment of an immutable binding
• E0013 — Missing return on a code path
• E0014 — Unwrap of a None optional
• E0015 — Import target not found
• E0016 — Generic trait bound not satisfied
• E0017 — Unknown or missing struct field
• E0018 — Recursion / stack usage limit exceeded
• E0019 — Z3 could not prove a contract clause
• E0020 — Effect/purity violation
• E0021 — dyn Trait object-safety violation