scp completes but ssh subprocess in deadlock with sshd

[Adrian Pronk]

I've just built openssh 3.1 for my Redhat 5.1 system (running on a 486
DX-66) using the latest zlib and openssl libraries.

Connecting to the machine with ssh seems to work fine (although it takes a
while to initiate a connection).

But when I transfer a file to the machine with scp, it seems to work fine
and the scp completes, but an ssh sub-process remains behind on the client
and an sshd sub-process remains behind on the host.  When I strace them,
the client is waiting on a socket and the host is waiting on three
different fd's (under 5.1, its hard to tell what they are without making an
effort :) ).

I did not compile the system on the target machine (which is my firewall).
My old development machine was a RH 5.1 box.  I bought a new box recently
and put RH 7.2 on it.  I copied the development RH 5.1 file system on to it
(including /dev).  I then chroot'ed to that directory , mounted a new /proc
and had my 5.1 development environment back.  I compiled (make install)
openSSL, zlib, openSSH on this and copied the likely output files to the
target machine.  I wouldn't think this development environment would break
anything.

Does anyone know off the top of their heads what the problem might be?  If
not, I'll get stuck in and have a look at the code and see if I can see
anything.

--
Adrian