(discussed below).

When preparing any change that is permitted by Go 1 compatibility
but may nonetheless break some existing programs,
we first engineer the change to keep as many existing programs working as possible.
For the remaining programs,
we define a new GODEBUG setting that
allows individual programs to opt back in to the old behavior.
A GODEBUG setting may not be added if doing so is infeasible,
but that should be extremely rare.

	if err != nil {
		t.Fatal("TempDir failed: ", err)
	}
	defer os.RemoveAll(tmpDir)

	// Build copy of test binary with debug symbols,
	// since the one running now may not have them.
	exepath := filepath.Join(tmpDir, "testaddr2line_test.exe")
	out, err := testenv.Command(t, testenv.GoToolPath(t), "test", "-c", "-o", exepath, "cmd/addr2line").CombinedOutput()
	if err != nil {

<a href="/pkg/runtime/"><code>runtime</code></a> and
<a href="/pkg/math/big/"><code>math/big</code></a>.
You can also examine what the compiler emits as assembly code
(the actual output may differ from what you see here):
</p>

<pre>
$ cat x.go
package main

func main() {
	println(3)
}
$ GOOS=linux GOARCH=amd64 go tool compile -S x.go        # or: go build -gcflags -S x.go

[runtime.Pinner].

The _GoString_ type also may not be pinned with [runtime.Pinner].
Because it includes a Go pointer, the memory it points to is only pinned
for the duration of the call; _GoString_ values may not be retained by C
code.

A Go function called by C code may return a Go pointer to pinned memory
(which implies that it may not return a string, slice, channel, and so
forth). A Go function called by C code may take C pointers as arguments,

No identifier may be declared twice in the same block, and
no identifier may be declared in both the file and package block.
</p>

<p>
The <a href="#Blank_identifier">blank identifier</a> may be used like any other identifier
in a declaration, but it does not introduce a binding and thus is not declared.
In the package block, the identifier <code>init</code> may only be used for

  - type: textarea
    id: what-did-you-do
    attributes:
      label: "What did you do?"
      description: "If possible, provide a recipe for reproducing the error. Starting with a Private/Incognito tab/window may help rule out problematic browser extensions."
    validations:
      required: true
  - type: textarea
    id: actual-behavior
    attributes:
      label: "What did you see happen?"
    validations:

		t.Errorf("error=%v, want %v", err, zt.Error)
		return
	}

	// bail if file is not zip
	if err == ErrFormat {
		return
	}

	// bail here if no Files expected to be tested
	// (there may actually be files in the zip, but we don't care)
	if zt.File == nil {
		return
	}

	if z.Comment != zt.Comment {
		t.Errorf("comment=%q, want %q", z.Comment, zt.Comment)
	}
	if len(z.File) != len(zt.File) {

Make sure that GO111MODULE is not set in the environment, or that it is
set to 'on' or 'auto', and if you use a go.work file, set GOWORK=off.

Requirements may be added, updated, and removed with 'go get'.
The vendor directory may be updated with 'go mod vendor'.
A typical sequence might be:

    cd src  # or src/cmd
    go get golang.org/x/net@master
    go mod tidy
    go mod vendor

	var whyOnlyPAX, whyOnlyGNU string
	switch h.Typeflag {
	case TypeReg, TypeChar, TypeBlock, TypeFifo, TypeGNUSparse:
		// Exclude TypeLink and TypeSymlink, since they may reference directories.
		if strings.HasSuffix(h.Name, "/") {
			return FormatUnknown, nil, headerError{"filename may not have trailing slash"}
		}
	case TypeXHeader, TypeGNULongName, TypeGNULongLink:

No identifier may be declared twice in the same block, and
no identifier may be declared in both the file and package block.
</p>

<p>
The <a href="#Blank_identifier">blank identifier</a> may be used like any other identifier
in a declaration, but it does not introduce a binding and thus is not declared.
In the package block, the identifier <code>init</code> may only be used for