pg_config --includedir is null

G'day

After a successful make install of postgresql-8.1.3 with msys and mingw
pg_config --includedir is null ...

I want to to show the correct includedir to allow libpqxx to compile.
Any clues on how to recompile postgres or pg_config to show the
correct directories?

Thanks in advance

--
Keith Hutchison
http://balance-infosystems.com http://realopen.org
http://www.kasamba.com/Keith-Hutchison

Output of pg_config
$ /c/usr/src/postgresql-8.1.3/src/bin/pg_config/pg_config.exe
BINDIR = c:/usr/src/POSTGR~1.3/src/bin/PG_CON~1
DOCDIR =
INCLUDEDIR =
PKGINCLUDEDIR =
INCLUDEDIR-SERVER =
LIBDIR =
PKGLIBDIR =
LOCALEDIR =
MANDIR =
SHAREDIR =
SYSCONFDIR =
PGXS =
CONFIGURE =
CC = gcc
CPPFLAGS = -I./src/include/port/win32 -DEXEC_BACKEND
-I../../../src/include/port/win32
CFLAGS = -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Winline
-Wdeclaration-after-statement -Wendif-labels -fno-strict-aliasing
CFLAGS_SL =
LDFLAGS = -Wl,--allow-multiple-definition
LDFLAGS_SL =
LIBS = -lpgport -lz -lwsock32 -lm -lws2_32 -lshfolder
VERSION = PostgreSQL 8.1.3