Errors & Warnings

What to do about the common ones is in Fix Language Errors.

Where an error is shown

Where	What it shows
`resonon run`, `resonon view console`, the REPL	The full text, with the location. A parse error adds the source line and a caret.
VSCode Problems panel and underlines	The text without the location, underlined where it happened, with the kind’s code beside it.

A location is path:line:column, or line:column for code that has no file. Some errors have no location, and print their text alone.

Parse error at /home/me/song/src/main.non:1:12: expected neg, pos, not, or primary
  |
1 | let x = 1 +;
  |            ^

resonon run exits with status 1 after an error.

When code stops

Error	What runs
A parse error	Nothing of the file or selection. Every parse error in it is reported, up to 100.
A definition repeated in one file or selection	Nothing of it. Every repeat is reported.
Any other error	Everything before the statement that raised it.
A warning	Everything; the warning is printed as `Warning: …`.

Kinds

The code is what VSCode shows beside the message.

Code	Text	Raised by
`parse`	`Parse error at L: …`	Code that does not fit the grammar, a note literal above MIDI 127 (`B9`: `Invalid note 'B9'`), or a definition written inside a function or block.
`runtime`	`Runtime error at L: …`	A failure with no kind of its own: a bad argument value, a failed operation.
`type`	`Type error at L: expected X, got Y`	A value of the wrong type for an operator, a function argument, a condition or an annotation.
`undefined_variable`	`Undefined variable 'x' at L`	A name that is not defined.
`undefined_function`	`Undefined function 'f' at L`	A call of a name that is not defined.
`undefined_method`	`Undefined method 'm' for type T at L`	A method the value’s type does not have.
`undefined_property`	`Undefined property 'p' for type T at L`	A field a class instance does not have.
`arity_mismatch`	`Arity mismatch at L: 'f' expects N arguments, got M`	Too few or too many arguments. `N` is a number, a range `min-max`, or `variadic`.
`division_by_zero`	`Division by zero at L`	`/` or `%` by `0`.
`index_out_of_bounds`	`Index out of bounds at L: index I is out of range for length N`	An array, tuple or string index past its end.
`assertion_failed`	`Assertion failed at L: message`	An `assert` whose condition is `false`. Without a message: `Assertion failed at L`.
`borrow_error`	`Borrow error at L: …`	A class instance changed while resonon itself still holds it. It should not happen; report it.
`private_access`	`Cannot access private 'x' in module 'm' at L`	A `private` definition used from outside its module.
`module_not_found`	`Runtime error at L: Module 'p' not found. Searched:` and each folder searched	A `use` path found in no search path.
`duplicate_definition`	`Duplicate definition at L: fn 'f' repeats the fn at L2.` and a line saying what to do	A name bound twice in one file or selection — by two definitions, a `let` and a definition, or a `use` and anything else.
`dsp`	`DSP error at L: …`	A `dsp` block that does not compile. See DSP Code.
`plugin_skipped`	`Runtime error at L: …`	A plugin that the plugin scan skipped after it crashed. The editor offers to retry it.
`version_mismatch`	`Runtime error at L: …`	Code from a project that needs a newer resonon than the server runs. The editor offers to restart the server.

L is the location.

Severity in the editor

The editor checks code as you type, without running it, and runs no code to confirm what it finds.

Found	Severity
After you evaluate: any error	Error
As you type: `parse`, `duplicate_definition`, `dsp`, `module_not_found`, `undefined_*`, `arity_mismatch`, `private_access`	Error
As you type: `type`, `runtime`, `division_by_zero`, `index_out_of_bounds`, `assertion_failed`, `borrow_error`	Warning

Errors found as you type stay until the code changes; errors from an evaluation clear at your next evaluation.

In Live Mode (online), a duplicate_definition between two top-level bindings in the file is not shown: each selection is evaluated on its own. File Mode (offline) shows them.

Editor-only diagnostics

These come from the language server, not from running code:

Code	Severity	Where	Meaning
`kit-unportable`	Information	`.non`	A `Kit("…")` whose kit is outside the project and not listed under `[local]`.
`kit-missing`	Warning	`resonon.toml`	A `[local] kits` entry found nowhere.
`kit-outside-project`	Information	`resonon.toml`	A `[local] kits` entry found only outside the project.
`kit-travels-anyway`	Hint	`resonon.toml`	A `[local] kits` entry for a kit that travels anyway — in the project, a dependency, or the kits resonon ships — so the entry does nothing.
`manifest-unknown-key`	Warning	`resonon.toml`	A key resonon does not read.
`manifest-syntax`	Error	`resonon.toml`	TOML that does not parse.