---
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.

_cgo_main.c:

	int main() { return 0; }
	void crosscall2(void(*fn)(void*), void *a, int c, uintptr_t ctxt) { }
	uintptr_t _cgo_wait_runtime_init_done(void) { return 0; }
	void _cgo_release_context(uintptr_t ctxt) { }
	char* _cgo_topofstack(void) { return (char*)0; }
	void _cgo_allocate(void *a, int c) { }
	void _cgo_panic(void *a, int c) { }
	void _cgo_reginit(void) { }

		log.Fatal(err)
	}
	s := string(bs)

	// Diagnose common mistakes people make,
	// since there is no apifmt to format these files.
	// The missing final newline is important for the
	// final release step of cat next/*.txt >go1.X.txt.
	// If the files don't end in full lines, the concatenation goes awry.
	if strings.Contains(s, "\r") {
		log.Printf("%s: contains CRLFs", filename)
		exitCode = 1
	}