}

	syscall.Close(fd)
	return true
}

func testMultiPathTCP(t *testing.T, envVar bool) {
	if envVar {
		t.Log("Test with GODEBUG=multipathtcp=1")
		t.Setenv("GODEBUG", "multipathtcp=1")
	} else {
		t.Log("Test with GODEBUG=multipathtcp=0")
		t.Setenv("GODEBUG", "multipathtcp=0")
	}

	ln := newLocalListenerMPTCP(t, envVar)

	// similar to tcpsock_test:TestIPv6LinkLocalUnicastTCP

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package x509

import (
	"internal/godebug"
	"sync"
	_ "unsafe" // for linkname
)

// systemRoots should be an internal detail,
// but widely used packages access it using linkname.
// Notable members of the hall of shame include:
//   - github.com/breml/rootcerts
//

	}
	runDebugOptionsTest(t, "TestSSE3DebugOption", "cpu.sse3=off")
}

func TestSSE3DebugOption(t *testing.T) {
	MustHaveDebugOptionsSupport(t)

	if godebug.New("#cpu.sse3").Value() != "off" {
		t.Skipf("skipping test: GODEBUG=cpu.sse3=off not set")
	}

	want := false
	if got := X86.HasSSE3; got != want {
		t.Errorf("X86.HasSSE3 expected %v, got %v", want, got)
	}

	{name: "asynctimerchan", atomic: &debug.asynctimerchan},
	{name: "cgocheck", value: &debug.cgocheck},
	{name: "clobberfree", value: &debug.clobberfree},
	{name: "disablethp", value: &debug.disablethp},
	{name: "dontfreezetheworld", value: &debug.dontfreezetheworld},
	{name: "efence", value: &debug.efence},
	{name: "gccheckmark", value: &debug.gccheckmark},
	{name: "gcpacertrace", value: &debug.gcpacertrace},

[short] skip

# Packages in std do not have an install target.
go list -f '{{.Target}}' fmt
! stdout .
go list -export -f '{{.Export}}' fmt
stdout $GOCACHE

# With GODEBUG=installgoroot=all, fmt has a target.
# (Though we can't try installing it without modifying goroot).
env GODEBUG=installgoroot=all
go list -f '{{.Target}}' fmt
stdout fmt\.a

# However, the fake packages "builtin" and "unsafe" do not.
go list -f '{{.Target}}' builtin unsafe

	// allow cmd/go to use it.
	s.Setenv("TESTGONETWORK", "")
	return true, nil
}

func hasGodebug(s *script.State, value string) (bool, error) {
	godebug, _ := s.LookupEnv("GODEBUG")
	for _, p := range strings.Split(godebug, ",") {
		if strings.TrimSpace(p) == value {
			return true, nil
		}
	}
	return false, nil
}

func hasGoexperiment(s *script.State, value string) (bool, error) {

// license that can be found in the LICENSE file.

package base

import (
	"fmt"
	"internal/godebug"
	"runtime"
	"strconv"
	"sync"
)

var NetLimitGodebug = godebug.New("#cmdgonetlimit")

// NetLimit returns the limit on concurrent network operations
// configured by GODEBUG=cmdgonetlimit, if any.
//
// A limit of 0 (indicated by 0, true) means that network operations should not
// be allowed.

flags are specified, as in 'go mod edit -fmt'.

The -module flag changes the module's path (the go.mod file's module line).

The -godebug=key=value flag adds a godebug key=value line,
replacing any existing godebug lines with the given key.

The -dropgodebug=key flag drops any existing godebug lines
with the given key.

The -require=path@version and -droprequire=path flags

			return
		}
		f.Module.Mod = module.Version{Path: s}

	case "godebug":
		if len(args) != 1 || strings.ContainsAny(args[0], "\"`',") {
			errorf("usage: godebug key=value")
			return
		}
		key, value, ok := strings.Cut(args[0], "=")
		if !ok {
			errorf("usage: godebug key=value")
			return
		}
		f.Godebug = append(f.Godebug, &Godebug{
			Key:    key,
			Value:  value,
			Syntax: line,
		})

These new behaviors are only enabled when the main Go program
is in a module with a `go.mod` `go` line using Go 1.23.0 or later.
When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)
can be used to revert back to asynchronous channel behaviors