improve fprintf related error handling

internal/backend/rest/rest_test.go

@@ -106,7 +106,7 @@ func runRESTServer(ctx context.Context, t testing.TB, dir, reqListenAddr string)
 					matched = true
 				}
 			}
-			fmt.Fprintln(os.Stdout, line) // print all output to console
+			_, _ = fmt.Fprintln(os.Stdout, line) // print all output to console
 		}
 	}()
 

internal/debug/debug.go

@@ -120,7 +120,7 @@ func goroutineNum() int {
 	runtime.Stack(b, false)
 	var num int
 
-	fmt.Sscanf(string(b), "goroutine %d ", &num)
+	_, _ = fmt.Sscanf(string(b), "goroutine %d ", &num)
 	return num
 }
 

internal/debug/round_tripper.go

@@ -42,7 +42,7 @@ func (rd *eofDetectReader) Close() error {
 			msg += fmt.Sprintf(", body: %q", buf)
 		}
 
-		fmt.Fprintln(os.Stderr, msg)
+		_, _ = fmt.Fprintln(os.Stderr, msg)
 		Log("%s: %+v", msg, errors.New("Close()"))
 	}
 	return rd.rd.Close()

internal/ui/termstatus/status.go

@@ -212,7 +212,7 @@ func (t *Terminal) runWithoutStatus(ctx context.Context) {
 			}
 
 			if _, err := io.WriteString(dst, msg.line); err != nil {
-				fmt.Fprintf(os.Stderr, "write failed: %v\n", err)
+				_, _ = fmt.Fprintf(os.Stderr, "write failed: %v\n", err)
 			}
 
 			if flush == nil {
@@ -220,16 +220,18 @@ func (t *Terminal) runWithoutStatus(ctx context.Context) {
 			}
 
 			if err := flush(); err != nil {
-				fmt.Fprintf(os.Stderr, "flush failed: %v\n", err)
+				_, _ = fmt.Fprintf(os.Stderr, "flush failed: %v\n", err)
 			}
 
 		case stat := <-t.status:
 			for _, line := range stat.lines {
 				// Ensure that each message ends with exactly one newline.
-				fmt.Fprintln(t.wr, strings.TrimRight(line, "\n"))
+				if _, err := fmt.Fprintln(t.wr, strings.TrimRight(line, "\n")); err != nil {
+					_, _ = fmt.Fprintf(os.Stderr, "write failed: %v\n", err)
+				}
 			}
 			if err := t.wr.Flush(); err != nil {
-				fmt.Fprintf(os.Stderr, "flush failed: %v\n", err)
+				_, _ = fmt.Fprintf(os.Stderr, "flush failed: %v\n", err)
 			}
 		}
 	}