I couldn't compile postgresql 7.3.1 under cygwin 1.3.18-1

Jason,

This is the error I got. What am I doing wrong?

gcc -O2 -Wall -Wmissing-prototypes -Wmissing-declarations
-I../../../src/
-DBUILDING_DLL -c -o pg_sema.o pg_sema.c
pg_sema.c: In function `InternalIpcSemaphoreCreate':
pg_sema.c:95: warning: implicit declaration of function `semget'
pg_sema.c:95: `IPC_CREAT' undeclared (first use in this function)
pg_sema.c:95: (Each undeclared identifier is reported only once
pg_sema.c:95: for each function it appears in.)
pg_sema.c:95: `IPC_EXCL' undeclared (first use in this function)
pg_sema.c: In function `IpcSemaphoreInitialize':
pg_sema.c:150: warning: implicit declaration of function `semctl'
pg_sema.c:150: `SETVAL' undeclared (first use in this function)
pg_sema.c: In function `IpcSemaphoreKill':
pg_sema.c:175: `IPC_RMID' undeclared (first use in this function)
pg_sema.c: In function `IpcSemaphoreGetValue':
pg_sema.c:193: `GETVAL' undeclared (first use in this function)
pg_sema.c: In function `IpcSemaphoreGetLastPID':
pg_sema.c:204: `GETPID' undeclared (first use in this function)
pg_sema.c: In function `IpcSemaphoreCreate':
pg_sema.c:263: `IPC_RMID' undeclared (first use in this function)
pg_sema.c: In function `PGSemaphoreLock':
pg_sema.c:390: storage size of `sops' isn't known
pg_sema.c:434: warning: implicit declaration of function `semop'
pg_sema.c:390: warning: unused variable `sops'
pg_sema.c: In function `PGSemaphoreUnlock':
pg_sema.c:455: storage size of `sops' isn't known
pg_sema.c:455: warning: unused variable `sops'
pg_sema.c: In function `PGSemaphoreTryLock':
pg_sema.c:489: storage size of `sops' isn't known
pg_sema.c:492: `IPC_NOWAIT' undeclared (first use in this function)
pg_sema.c:489: warning: unused variable `sops'
make[3]: *** [pg_sema.o] Error 1
make[3]: Leaving directory `/usr/src/postgresql-7.3.1/src/backend/port'
make[2]: *** [port-recursive] Error 2
make[2]: Leaving directory `/usr/src/postgresql-7.3.1/src/backend'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/usr/src/postgresql-7.3.1/src'
make: *** [all] Error 2
make: *** No rule to make target `intall'. Stop.