Error Codes

Every Turbo compiler diagnostic includes a unique error code. Use turbo explain E0100 to look up any code from the command line.

$ turbo explain E0100
E0100: Type mismatch
  The compiler expected one type but found another.

Parse Errors (E0001--E0099)

Code	Description
`E0001`	Unexpected token during parsing
`E0002`	Expected identifier
`E0003`	Maximum nesting depth exceeded
`E0004`	Invalid import syntax
`E0005`	Invalid string interpolation syntax
`E0006`	Unexpected end of file
`E0007`	Invalid attribute
`E0008`	Invalid expression

Type Errors (E0100--E0199)

Code	Description
`E0100`	Type mismatch
`E0101`	Cannot perform arithmetic on non-numeric type
`E0102`	Mismatched types in arithmetic operation
`E0103`	Cannot compare incompatible types
`E0104`	Expected bool in logical operation
`E0105`	Cannot negate non-numeric type
`E0106`	Cannot apply logical not to non-bool type
`E0107`	If/else branches have different types
`E0108`	Match arms have different types
`E0109`	Function return type does not match body
`E0110`	Type annotation does not match value type
`E0111`	Cannot assign incompatible type to variable
`E0112`	Cannot assign incompatible type to struct field
`E0113`	Cannot assign incompatible type to array element
`E0114`	Array elements must all have the same type
`E0115`	Cannot infer type of empty array literal
`E0116`	If condition must be bool
`E0117`	While condition must be bool
`E0118`	?? inner type does not match default type
`E0119`	?? requires an optional type on the left
`E0120`	? operator requires a Result type
`E0121`	? can only be used in a function returning Result
`E0122`	Range bounds must be integers
`E0123`	Array index must be an integer
`E0124`	Cannot index into non-array type
`E0125`	Closure body type does not match declared return type
`E0126`	Cannot infer type of closure parameter
`E0127`	Unknown closure return type
`E0128`	Struct equality requires @derive(Eq)
`E0129`	Cannot use ordering comparison on struct type
`E0130`	Incompatible type in compound assignment
`E0131`	Type parameter inference conflict
`E0132`	Pattern type incompatible with match subject
`E0133`	Builtin function argument type mismatch
`E0134`	Cannot call method on this type
`E0135`	Cannot access field on this type
`E0136`	Expression nesting too deep
`E0137`	Unsupported compound assignment operator

Pattern/Match Errors (E0200--E0299)

Code	Description
`E0200`	Match expression is not exhaustive
`E0201`	Match expression has no arms
`E0202`	Match guard must be bool
`E0203`	Variant destructure binding count does not match field count
`E0204`	Enum variant requires arguments but none were provided

Name Resolution Errors (E0300--E0399)

Code	Description
`E0300`	Undefined variable
`E0301`	Undefined function
`E0302`	Undefined struct
`E0303`	Undefined enum
`E0304`	Undefined trait
`E0305`	Unknown type name
`E0306`	Struct is already defined
`E0307`	Enum is already defined
`E0308`	Function is already defined
`E0309`	Trait is already defined
`E0310`	Method is already defined for this type
`E0311`	Constant is already defined
`E0312`	Agent is already defined
`E0313`	Cannot redefine builtin function
`E0314`	No main function found
`E0315`	Struct has no such field
`E0316`	Enum has no such variant
`E0317`	No such method found on type
`E0318`	Missing field in struct literal
`E0319`	Unknown derive trait
`E0320`	Impl block for undefined type
`E0321`	Undefined tool function referenced in agent
`E0322`	Function referenced in agent is not a tool fn
`E0323`	Unknown type in trait method signature
`E0324`	Unknown return type

Codegen Errors (E0400--E0499)

Code	Description
`E0400`	Internal code generation error
`E0401`	Undefined variable during code generation
`E0402`	Undefined function during code generation
`E0403`	Unsupported expression during code generation
`E0404`	Linker or build tool error
`E0405`	Cranelift backend error
`E0406`	Missing function definition

Misc Errors (E0500--E0599)

Code	Description
`E0500`	Wrong number of arguments
`E0501`	Cannot assign to immutable variable
`E0502`	Cannot assign to field of immutable variable
`E0503`	Cannot assign to index of immutable variable
`E0504`	Test function must have no parameters
`E0505`	Test function must have no return type
`E0506`	Constant must be a literal value
`E0507`	break can only be used inside a loop
`E0508`	continue can only be used inside a loop
`E0509`	Required trait method is not implemented
`E0510`	Trait impl method return type does not match trait definition
`E0511`	Agent does not accept field initializers
`E0512`	Only named function calls are supported
`E0513`	Builtin function argument count error