t.Errorf("Fchmodat: failed to change mode: expected %v, got %v", 0444, fi.Mode())
	}

	err = syscall.Fchmodat(_AT_FDCWD, "symlink1", 0444, _AT_SYMLINK_NOFOLLOW)
	if err != syscall.EOPNOTSUPP {
		t.Fatalf("Fchmodat: unexpected error: %v, expected EOPNOTSUPP", err)
	}
}

func TestMain(m *testing.M) {
	if os.Getenv("GO_DEATHSIG_PARENT") == "1" {
		deathSignalParent()
	} else if os.Getenv("GO_DEATHSIG_CHILD") == "1" {

	ENOTNAM         = syscall.Errno(0x76)
	ENOTRECOVERABLE = syscall.Errno(0x83)
	ENOTSOCK        = syscall.Errno(0x58)
	ENOTSUP         = syscall.Errno(0x5f)
	ENOTUNIQ        = syscall.Errno(0x4c)
	EOPNOTSUPP      = syscall.Errno(0x5f)
	EOVERFLOW       = syscall.Errno(0x4b)
	EOWNERDEAD      = syscall.Errno(0x82)
	EPFNOSUPPORT    = syscall.Errno(0x60)
	EPROTO          = syscall.Errno(0x47)

	ENOTNAM         = syscall.Errno(0x76)
	ENOTRECOVERABLE = syscall.Errno(0x83)
	ENOTSOCK        = syscall.Errno(0x58)
	ENOTSUP         = syscall.Errno(0x5f)
	ENOTUNIQ        = syscall.Errno(0x4c)
	EOPNOTSUPP      = syscall.Errno(0x5f)
	EOVERFLOW       = syscall.Errno(0x4b)
	EOWNERDEAD      = syscall.Errno(0x82)
	EPFNOSUPPORT    = syscall.Errno(0x60)
	EPROTO          = syscall.Errno(0x47)

	ENOTNAM         = syscall.Errno(0x76)
	ENOTRECOVERABLE = syscall.Errno(0x83)
	ENOTSOCK        = syscall.Errno(0x58)
	ENOTSUP         = syscall.Errno(0x5f)
	ENOTUNIQ        = syscall.Errno(0x4c)
	EOPNOTSUPP      = syscall.Errno(0x5f)
	EOVERFLOW       = syscall.Errno(0x4b)
	EOWNERDEAD      = syscall.Errno(0x82)
	EPFNOSUPPORT    = syscall.Errno(0x60)
	EPROTO          = syscall.Errno(0x47)

		if err == ENOSYS {
			// fchmodat2 isn't available. If the flags are known to be valid,
			// return EOPNOTSUPP to indicate that fchmodat doesn't support them.
			if flags&^(_AT_SYMLINK_NOFOLLOW|_AT_EMPTY_PATH) != 0 {
				return EINVAL
			} else if flags&(_AT_SYMLINK_NOFOLLOW|_AT_EMPTY_PATH) != 0 {
				return EOPNOTSUPP
			}
		}
		return err
	}
	return fchmodat(dirfd, path, mode)
}