Sets much smaller than they used to be?

["Ian D. Leroux" <idleroux%fastmail.fm@localhost>]

I rebuilt/reinstalled amd64 -current on the weekend, and noticed
(during etcupdate) that many lines had been deleted from the /etc/mtree
files. For instance, many of the files in /usr/include (e.g. stdio.h)
don't appear anywhere in the lists under /etc/mtree.

At the same time, I've discovered that at least one file
(/usr/include/sys/audioio.h) is not getting installed/updated when I
run ./build.sh install=/
That file happened to have changed between my last build in late
February and the most recent one, which made the failure to install the
updated version more obvious.

Might these two observations be related?  Did something change recently
about the way the set lists are put together?

--
IDL