---
title: "Go, Backwards Compatibility, and GODEBUG"
layout: article
---

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This document is kept in the Go repo, not x/website,
because it documents the full list of known GODEBUG settings,
which are tied to a specific release.
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## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.

pkg go/token, method (*File) MergeLine(int)
pkg html/template, type Template struct, Tree *parse.Tree
pkg image/color/palette, var Plan9 []color.Color
pkg image/color/palette, var WebSafe []color.Color
pkg image/draw, method (Op) Draw(Image, image.Rectangle, image.Image, image.Point)
pkg image/draw, type Drawer interface { Draw }