Problem installing Postgresql

I am running OpenLinux 2.3 (Caldera) out of the box. Trying to install
PostGreSQL I seem to be unable to get past the 'make' process. Errors I
get at the end of the process are:

make[3]: *** [pg_backup_custom.o] Error 1
make[3]: Leaving directory `/addon/postgresql-7.1/src/bin/pg_dump'
make[2]: *** [all] Error 2
make[3]: Leaving directory `/addon/postgresql-7.1/src/bin/'
make[1]: *** [all] Error 2
make[3]: Leaving directory `/addon/postgresql-7.1/src'
make: *** [all] Error 2

Some examples of errors I see in the output are:

pg_backup_custom.c: In function `_DoDeflate':
pg_backup_custom.c:925:`z_streamp' undeclared (first use in this function)
pg_backup_custom.c:925: parse error before `zp'
pg_backup_custom.c:928: 'ctx' undecleared (first use in this function)

Please note that I am fairly new to Linux so a lot of this isn't making
sense. Any ideas?