cmd/testwrapper: fix for go1.24icio/go1.24-testwrapper

Updates #15015

Signed-off-by: Paul Scott <paul@tailscale.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/cmd/testwrapper/testwrapper_test.go b/cmd/testwrapper/testwrapper_test.go
index fb2ed2c52..ace53ccd0 100644
--- a/cmd/testwrapper/testwrapper_test.go
+++ b/cmd/testwrapper/testwrapper_test.go
@@ -11,6 +11,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"strings"
 	"sync"
 	"testing"
 )
@@ -154,24 +155,24 @@ func TestBuildError(t *testing.T) {
 		t.Fatalf("writing package: %s", err)
 	}
 
-	buildErr := []byte("builderror_test.go:3:1: expected declaration, found derp\nFAIL	command-line-arguments [setup failed]")
+	wantErr := "builderror_test.go:3:1: expected declaration, found derp\nFAIL"
 
 	// Confirm `go test` exits with code 1.
 	goOut, err := exec.Command("go", "test", testfile).CombinedOutput()
 	if code, ok := errExitCode(err); !ok || code != 1 {
-		t.Fatalf("go test %s: expected error with exit code 0 but got: %v", testfile, err)
+		t.Fatalf("go test %s: got exit code %d, want 1 (err: %v)", testfile, code, err)
 	}
-	if !bytes.Contains(goOut, buildErr) {
-		t.Fatalf("go test %s: expected build error containing %q but got:\n%s", testfile, buildErr, goOut)
+	if !strings.Contains(string(goOut), wantErr) {
+		t.Fatalf("go test %s: got output %q, want output containing %q", testfile, goOut, wantErr)
 	}
 
 	// Confirm `testwrapper` exits with code 1.
 	twOut, err := cmdTestwrapper(t, testfile).CombinedOutput()
 	if code, ok := errExitCode(err); !ok || code != 1 {
-		t.Fatalf("testwrapper %s: expected error with exit code 0 but got: %v", testfile, err)
+		t.Fatalf("testwrapper %s: got exit code %d, want 1 (err: %v)", testfile, code, err)
 	}
-	if !bytes.Contains(twOut, buildErr) {
-		t.Fatalf("testwrapper %s: expected build error containing %q but got:\n%s", testfile, buildErr, twOut)
+	if !strings.Contains(string(twOut), wantErr) {
+		t.Fatalf("testwrapper %s: got output %q, want output containing %q", testfile, twOut, wantErr)
 	}
 
 	if testing.Verbose() {