What causes "unrecognized environment" in golang/go?

Treat the error as informational; version detection is explicitly best-effort.

unrecognized environment

Error message

unrecognized environment

What it means

On the js/wasm target, osinfo.Version() makes a best-effort attempt to detect the runtime by checking for a global 'process' object with a 'version' property (Node.js). If that is absent, the environment is unrecognized. This is purely for log readability (e.g. build.golang.org) — it is not a hard failure path.

Source

Thrown at src/cmd/internal/osinfo/os_js.go:24

package osinfo

import (
	"fmt"
	"syscall/js"
)

// Version returns the OS version name/number.
func Version() (string, error) {
	// Version detection on Wasm varies depending on the underlying runtime
	// (browser, node, etc), nor is there a standard via something like
	// WASI (see https://go.dev/issue/31105). For now, attempt a few simple
	// combinations for the convenience of reading logs at build.golang.org
	// and local development. It's not a goal to recognize all environments.
	if v, ok := node(); ok {
		return "Node.js " + v, nil
	}
	return "", fmt.Errorf("unrecognized environment")
}

func node() (version string, ok bool) {
	// Try the https://nodejs.org/api/process.html#processversion API.
	p := js.Global().Get("process")
	if p.IsUndefined() {
		return "", false
	}
	v := p.Get("version")
	if v.IsUndefined() {
		return "", false
	}
	return v.String(), true
}

View on GitHub (pinned to b6b368adc5)

Solutions

Treat the error as informational; version detection is explicitly best-effort.
Run under Node.js if a version string is genuinely needed.

Defensive patterns

Strategy: fallback

Try / catch

// v, err := osinfo.Version()
// if err != nil {
//     // js/wasm best-effort detection failed; degrade gracefully
//     v = "unknown (js/wasm)"
// }

Prevention

Treat osinfo.Version on js/wasm as best-effort for logging only.
Run under Node.js if a version string is genuinely required.
Do not gate behavior on a non-empty version under js/wasm.

When it happens

Trigger: Calling osinfo.Version() in a js/wasm build running in a JS environment without 'process.version' — e.g. a plain browser, a minimal JS shell, or an older engine.

Common situations: Running a Go js/wasm binary in a browser-only context, or in a custom/embedded JS runtime that does not expose Node's process API.

Related errors

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/fe3d577f86f1114c. Report an issue: GitHub.