win32 pg_autovacuum make error

I have just started seeing the following on win32:

make[1]: Entering directory
`/home/pgrunner/pgbuildfarm/root/HEAD/pgsql.blurfl/contrib/pg_autovacuum'
gcc -O2 -fno-strict-aliasing -Wall -Wmissing-prototypes
-Wmissing-declarations pg_autovacuum.o -L../../src/interfaces/libpq -lpq
-L../../src/port -lpgport -lwsock32 -lm -lws2_32 -o pg_autovacuum
pg_autovacuum.o(.text+0xae9):pg_autovacuum.c: undefined reference to
`DLNewElem'
pg_autovacuum.o(.text+0xaf8):pg_autovacuum.c: undefined reference to
`DLAddTail'
pg_autovacuum.o(.text+0xc2d):pg_autovacuum.c: undefined reference to
`DLRemove'
pg_autovacuum.o(.text+0x101a):pg_autovacuum.c: undefined reference to
`DLNewList'
pg_autovacuum.o(.text+0x1036):pg_autovacuum.c: undefined reference to
`DLNewElem'
pg_autovacuum.o(.text+0x103f):pg_autovacuum.c: undefined reference to
`DLAddHead'
pg_autovacuum.o(.text+0x11a2):pg_autovacuum.c: undefined reference to
`DLNewList'
pg_autovacuum.o(.text+0x14d3):pg_autovacuum.c: undefined reference to
`DLNewElem'
pg_autovacuum.o(.text+0x14df):pg_autovacuum.c: undefined reference to
`DLAddTail'
pg_autovacuum.o(.text+0x16ad):pg_autovacuum.c: undefined reference to
`DLRemove'
pg_autovacuum.o(.text+0xc57):pg_autovacuum.c: undefined reference to
`DLFreeElem'
pg_autovacuum.o(.text+0xcbe):pg_autovacuum.c: undefined reference to
`DLFreeList'
pg_autovacuum.o(.text+0x16f5):pg_autovacuum.c: undefined reference to
`DLFreeElem'
pg_autovacuum.o(.text+0x17ae):pg_autovacuum.c: undefined reference to
`DLFreeList'
make[1]: *** [pg_autovacuum] Error 1
make[1]: Leaving directory
`/home/pgrunner/pgbuildfarm/root/HEAD/pgsql.blurfl/contrib/pg_autovacuum'
make: *** [all] Error 2

Not sure what has changed ....

cheers

andrew