[Exim] Exim 4.31 Solaris compile problem

Hi

I'm having trouble building exim 4.31 on a fairly old Solaris 2.5.1 box. I
can get exim versions up to 4.12 to compile ok on this platform. However, the
following occurs both with Sun's cc and gcc when building exim 4.31:

[earlier build lines snipped]

gcc -c -O -I.    match.c
gcc -c -O -I.    moan.c
gcc -c -O -I.    os.c
../src/os.c: In function `os_getloadavg':
In file included from os.c:2:
../src/os.c:376: union has no member named `ui32'
*** Error code 1
make: Fatal error: Command failed for target `os.o'
Current working directory /mnt/users/gay/exim/exim-4.31/build-SunOS5-5.5-sparc
*** Error code 1
make: Fatal error: Command failed for target `go'

This has me baffled, as there is no mention of 'ui32' in os.c (or anywhere
else I looked).

I have no problems compiling 4.31 on Solaris 2.6, 7 or 8. But for various
reasons I need an exim binary for this old Solaris 2.5.1 machine.

Any help gratefully appreciated!

Andrew Gay
Bristol, UK