---
title: "compat_default_changed — error code"
description: "Aontu error code compat_default_changed: class compat — a change breaks an earlier version. Introduced in 0.53.0."
source: "https://aontu.dev/errors/compat_default_changed/"
---

[← every error code](https://aontu.dev/errors)

# `compat_default_changed`

Class

[`compat`](https://aontu.dev/errors#compat)

Since

`0.53.0`

Kind

fixed code

## What it means

a change breaks an earlier version.

## What to do

that is `aontu subsume` / `aontu breaking` talking: widen the change or version it

## Where this comes from

[`test/spec/errcodes.tsv`](https://github.com/aontu-lang/aontu/blob/main/test/spec/errcodes.tsv), the shared registry both implementations execute and assert set equality against. The _message text_ is deliberately not reproduced here: the engines are its catalogue, and a copy on this site would be a second source of truth for something already generated once. To read it, run the engine — or see [the skill's error-code guide](https://github.com/aontu-lang/aontu/blob/main/docs/skill/error-codes.md).

This page as data: [`/errors/compat_default_changed.json`](https://aontu.dev/errors/compat_default_changed.json)