difftime construction fails with pre-appended class

[ashbaldry]

There seems to be an error for constructing a difftime object when there is a class prior to it.

x <- structure(
  c(
    NA, 74269, 39024, 64597, 24937, NA, NA, 50690, 19113,
    10261, 44113, 17768, 8178, 86191, 22670, 1324, 55435, 5775, 4278
  ),
  class = c("hms", "difftime"),
  units = "secs"
)
constructive::construct(x)

Error in `constructive::construct()`:
! {constructive} could not build the requested code.
Caused by error in `if (protect && (mode == "symbol" || (mode == "name" && !uses_u))) ...`:
! missing value where TRUE/FALSE needed

[moodymudskipper]

Thanks a lot, this was not diff time specific but a more general issue in attribute repair, I'm glad you spotted this.