Weird regression with -current after Jan 31st

[Scott Ellis <scotte%intrepid.warped.com@localhost>]

I was doing typical testing of a -current kernel with a 
less-than-current userland, before installing all of userland, and ran 
into a weird regression problem.

With an amd64 userland and kernel from Jan 31st my Apache and Samba 
installations work fine.  Updating to a kernel from today (Feb 20), 
software from both those installations (but seemingly ONLY those 
installations!) immediately exit with an abort trap.

Running ktruss shows that it's not even trying to exec the target binary:

intrepid# ktruss -di ./htdigest
    75      1 ktruss   fktrace                     = 0
    75      1 ktruss   emul(netbsd)
    75      1 ktruss   fcntl(0x4, 0x3, 0)          = 1
    75      1 ktruss   fcntl(0x4, 0x4, 0x1)        = 0

as opposed to:

 601      1 ktruss   fktrace                     = 0
   601      1 ktruss   emul(netbsd)
   601      1 ktruss   fcntl(0x4, 0x3, 0)          = 1
   601      1 ktruss   fcntl(0x4, 0x4, 0x1)        = 0
   601      1 htdigest execve("./htdigest", 0x7f7fffffd810, 
0x7f7fffffd820) JUST
RETURN
   601      1 htdigest emul(netbsd)
(etc. etc.)


I've tried using a libc.so.12.171 from today, and that changed nothing. 
 For reference, htdigest needs:
htdigest:
        -lc.12 => /usr/lib/libc.so.12
        -lm.0 => /usr/lib/libm.so.0
        -lexpat.1 => /software/apache-2.2.14/lib/libexpat.so.1
        -lcrypt.1 => /usr/lib/libcrypt.so.1
        -lpthread.1 => /usr/lib/libpthread.so.1
        -lapr-1.3 => /software/apache-2.2.14/lib/libapr-1.so.3
        -laprutil-1.3 => /software/apache-2.2.14/lib/libaprutil-1.so.3


UPDATING doesn't show anything relevant since Jan 31, so I'm at a loss 
as to what could be causing this.

Ideas?

        ScottE