Bug#1073608: Bug#1074014: Bug#1073622: Bug#1073608: mksh, pax: no move to /usr going to happen, because:

[Thorsten Glaser]

(Another data point is that there’s versions of mksh with
version numbers larger than what’s in sid around in my own
repo, for those wanting to follow CVS snapshots more closely,
backported to all versions up to sarge, so bookworm users
can very well have mksh packages with a version number that
is greater than what will be in trixie so anything that relies
on version numbers for transitioning will also not work.)