Validation Rules

The transpiler reports diagnostics with short codes. Full text lives in cambrian-lang docs/LANGUAGE.md and cambrian-transpiler/src/validate/. Below is a public-target highlights list (EVM / Lean / Container).

Families

Prefix	Concern
V	Entity / route / member / phase / deploy / match
E	Domain EVM / Solidity-language compatibility
L	Lean language / Lean–EVM pair
T	`test` / `property` / `fuzz`
I	`invariant`
F	`project.yaml`
W	Warnings / lints

Notable V codes

Code	Summary
V27 / V28	Route-level vs per-phase `where` vs `var` scoping
V29	Forbidden actions inside action-level `for`
V30 / V31	`extern entity` uniqueness / route uniqueness
V32 / V33	`deploy` / `from` arity (V33 is Domain EVM)
V34 / V35	Unknown / mistyped `emit`
V36	More than three `indexed` event params (EVM)
V38 / V39	Unknown / mistyped `throw Name`
V40 / V41	`receive` / `fallback` shape and uniqueness (EVM)
V42	`return(value)` without `-> T`
V43	`^member` outside transform bodies
V45	Duplicate `deploy` collision risk
V46–V53	Hex-address ambiguity, match exhaustiveness, `if` without else, bare stdlib (V49), type bridges (V50), unused `let`, record cycles, `let some` patterns

Notable E codes (EVM / Solidity)

Code	Summary
E07 / E17–E21 / E23	Solidity lowering limits (iterators, maps, tuples, casts)
E09	`from` → `require(msg.sender == …)` (warning)
E12	`evm::` off the EVM domain
E16	Unknown namespace / `address_of` where CREATE2 addresses are not emitted / encode misuse
E22	Typed send to unknown entity (declare `extern entity`)

Notable L codes (Lean)

Code	Summary
L5 / L6	Vacuous throw / return expectations
L8	Send dest not a static in-program address
L9 / L11	Failing self-call without a fail surface
L10 / L12	Warnings: sends inside invariant steps; TVM `rescue`/`recover` dropped on Lean
L13 / L14	Missing crypto lowering / unknown types

Notable T / I / F / W

Code	Summary
T10–T12, T15–T23	Property params, assume/bound placement, `with` vs `ctx`, instance bindings
T38	Boolean `expect` is not boolean-shaped, mentions `result` on a route with no return type, or mentions `result` when that name is already a parameter, `let`, or member
I1–I6, I8–I16	Actions, checks, multi-entity qualification, `trace::*`
F1 / F3	Coverage requires parent enabled; engine name
F4	Imported file (in-language `import` or yaml `imports:`) declares `entity` / `test` / `fuzz` / `invariant`
F5	yaml `imports:` or a bare `import "…"` did not resolve against the first search directory or any `library_paths` root
W7 / W8	Fuzz fallback types; unpinned forall in concrete tests

Many legacy platform constructs produce E-family diagnostics on EVM; prefer writing portable Cambrian that stays within msg:: / sys:: / std:: / evm:: as documented in this book.