cc1 = "clang"
				break
			}
		}
	}
	cc, err := quotedSplit(cc1)
	if err != nil {
		fatalf("split CC: %v", err)
	}
	var ccHelp = append(cc, "--help")

	if output, err := exec.Command(ccHelp[0], ccHelp[1:]...).CombinedOutput(); err != nil {
		outputHdr := ""
		if len(output) > 0 {
			outputHdr = "\nCommand output:\n\n"
		}
		fatalf("cannot invoke C compiler %q: %v\n\n"+