debug: use strings.Builder

Change-Id: I59db11212758b478248f34c031501a167335348c
Reviewed-on: https://go-review.googlesource.com/c/go/+/428257
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/debug/buildinfo/buildinfo_test.go b/src/debug/buildinfo/buildinfo_test.go
index 3c7aafa7fffd2532a3aea60a29dbbfd08eb7c052..a0a816be17f42726a54121d6e1d21dd9f24cfcf9 100644 (file)
--- a/src/debug/buildinfo/buildinfo_test.go
+++ b/src/debug/buildinfo/buildinfo_test.go
@@ -80,13 +80,13 @@ func TestReadFile(t *testing.T) {
                cmd := exec.Command(testenv.GoToolPath(t), "build", "-o="+outPath, "-buildmode="+buildmode)
                cmd.Dir = dir
                cmd.Env = append(os.Environ(), "GO111MODULE=on", "GOOS="+goos, "GOARCH="+goarch)
-               stderr := &bytes.Buffer{}
+               stderr := &strings.Builder{}
                cmd.Stderr = stderr
                if err := cmd.Run(); err != nil {
                        if badmodeMsg := badmode(goos, goarch, buildmode); strings.Contains(stderr.String(), badmodeMsg) {
                                t.Skip(badmodeMsg)
                        }
-                       t.Fatalf("failed building test file: %v\n%s", err, stderr.Bytes())
+                       t.Fatalf("failed building test file: %v\n%s", err, stderr.String())
                }
                return outPath
        }
@@ -106,13 +106,13 @@ func TestReadFile(t *testing.T) {
                cmd := exec.Command(testenv.GoToolPath(t), "build", "-o="+outPath, "-buildmode="+buildmode)
                cmd.Dir = pkgDir
                cmd.Env = append(os.Environ(), "GO111MODULE=off", "GOPATH="+gopathDir, "GOOS="+goos, "GOARCH="+goarch)
-               stderr := &bytes.Buffer{}
+               stderr := &strings.Builder{}
                cmd.Stderr = stderr
                if err := cmd.Run(); err != nil {
                        if badmodeMsg := badmode(goos, goarch, buildmode); strings.Contains(stderr.String(), badmodeMsg) {
                                t.Skip(badmodeMsg)
                        }
-                       t.Fatalf("failed building test file: %v\n%s", err, stderr.Bytes())
+                       t.Fatalf("failed building test file: %v\n%s", err, stderr.String())
                }
                return outPath
        }