I had asked Stephen about that; he said that he made a change in manconf.c
to cope with buggy nroff implementations on some platforms.
Unfortunately, the result writes out man pages that cut off the H of MATCH,
all but the first directory of $PATH, and anything from a pipe symbol on
in the definition of $SHELLMETAS and in the expansions of ^TO, ^TO_,
^FROM_DAEMON, and ^FROM_MAILER. The actual binary is unaffected.
There are some *legitimate* updates to the man pages, so I wouldn't suggest
simply using the 3.11pre4 versions, but if you don't have the time to do all
the individual fixes, the 3.11pre4 versions may be better than the garbled
3.11pre6 copies.
Maybe another alternative is to use the 3.11pre4 version of src/manconf.c and
redo "make mans" with the rest of the 3.11pre6 source? Personally, I haven't
the guts to try that.