Buildfarm failure - pl/tcl on snake

CVS HEAD is consistently failing on snake in pl/tcl, whilst
REL8_0_STABLE is passing just fine.
 select * from T_pkey1 order by key1 using @<, key2;  key1 |         key2         |                   txt

------+----------------------+------------------------------------------
-     1 | KEY1-3               | should work
     1 | key1-1               | test key
     1 | key1-2               | test key
     1 | key1-3               | test key
     2 | key2-3               | test key
     2 | key2-9               | test key
 (6 rows)
--- 166,175 ---- select * from T_pkey1 order by key1 using @<, key2;  key1 |         key2         |
txt

------+----------------------+------------------------------------------     1 | key1-1               | test key
     1 | key1-2               | test key
     1 | key1-3               | test key

+     1 | KEY1-3               | should work
     2 | key2-3               | test key
     2 | key2-9               | test key
 (6 rows)

Loris, the only other Win32 box with TCL, is green. Does anyone know
what might be causing this?

Regards, Dave.