}
	_, err = fmt.Fprintf(f, "mode: %s\n", cfg.BuildCoverMode)
	if err != nil {
		base.Fatalf("%v", err)
	}
	coverMerge.f = f
}

// mergeCoverProfile merges file into the profile stored in testCoverProfile.
// It prints any errors it encounters to ew.
func mergeCoverProfile(ew io.Writer, file string) {
	if coverMerge.f == nil {
		return
	}
	coverMerge.Lock()
	defer coverMerge.Unlock()

				if coverMerge.f != nil {
					cp := coverProfTempFile(a)
					if err := work.WriteCoverageProfile(b, a, mf, cp, stdout); err != nil {
						return err
					}
					mergeCoverProfile(stdout, cp)
				}
			}
		}
		if reportNoTestFiles {
			fmt.Fprintf(stdout, "?   \t%s\t[no test files]\n", p.ImportPath)
		}
		return nil
	}

	var buf bytes.Buffer