installation of v6.4.2 failed on digital unix 4.0

Hi,

OS: Digital unix 4.0, hardware: alpha

When I installed postgresql-6.4.2, it stopped because gcc failed to
compile some files under src/backend/storage/buffer and ipc. As a result,
the associated SUBSYS.o could't be generated. All errors
are related to function 'tas' defined in include/storage/s_lock.h. Some
error message is attached. I did the configure using

./configure --prefix=/usr/local/pgsql --with-template=alpha --with-perl

then using gmake to compile, gcc version is 2.7.2.3. flex version is 2.5.4.

The only extra action is to touch src/backend/parser/gram.c to bypass the
yacc to gram.y.

Could you tell me why it failed? (BTW, I have got v6.3.2 running before)
Any help will be appreciated!

Wuyin
wlin(at)atmgcm(dot)msrc(dot)sunysb(dot)edu

=============================error message=============
../../../include/storage/s_lock.h: In function `tas':
In file included from buf_init.c:29:
../../../include/storage/s_lock.h:102: aggregate value used where an
integer was expected
buf_init.c: In function `InitBufferPool':
buf_init.c:234: incompatible types in assignment
../../../include/storage/s_lock.h: At top level:
../../../include/storage/s_lock.h:85: warning: `tas' defined but not used
gmake[3]: *** [buf_init.o] Error 1
...

*** No rule to make target `buffer/SUBSYS.o'. Stop.