Radar · Go · #003 · Week 41 · Oct 5 – 11, 2026

Decouple export data formats used by compiler and x/tools

Worth knowingecosystem

What changed: The proposal to separate the compiler’s export format from the tools’ export format was accepted; a new cmd/export tool will produce tools‑readable export data, and go list -export will follow the tools format.
Production impact: The source does not say.
Try it: Run go list -export on a package and inspect the generated file; compare it with the output of the new cmd/export tool (available in the development version).
Source: github.com/golang/go/issues/79427

Understand it, then run it

Export data is a compact binary file that the Go compiler writes so that tools can understand the types defined in a package. Today the compiler and the x/tools library both read the same export format. The proposal accepted on 2026‑10‑08 separates those formats. A new command, cmd/export, will create export files in the format that tools expect, and go list -export will point to those files instead of the compiler’s object file. The compiler’s own export format will become internal‑only.

Run it now

Todaygo

package main

import (
	"encoding/json"
	"fmt"
	"os/exec"
)

type ListInfo struct {
	Export string `json:"Export"`
}

func main() {
	// Run `go list -json -export` on the standard library package fmt.
	// This demonstrates the current Export field, which points to a compiler‑produced .a file.
	cmd := exec.Command("go", "list", "-json", "-export", "fmt")
	out, err := cmd.Output()
	if err != nil {
		panic(err)
	}
	var info ListInfo
	if err := json.Unmarshal(out, &info); err != nil {
		panic(err)
	}
	fmt.Println("Export file path (current behavior):")
	fmt.Println(info.Export)
}

What it printed when we ran it on Go 1.27.1

Export file path (current behavior):
/opt/gocache/88/88b5e23569a6a57669612c078d181f9d823b92f8c2e63ef69ecc277114529d41-d

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Written by gpt-oss-120b from the linked source · claims checked against the sources · human-reviewed