Index: src/backend/distributed/Makefile
--- src/backend/distributed/Makefile.orig	2018-11-28 08:42:05.000000000 +0100
+++ src/backend/distributed/Makefile	2018-11-29 19:11:45.280063000 +0100
@@ -33,7 +33,7 @@
 	$(patsubst $(citus_abs_srcdir)/%.c,%.o,$(foreach dir,$(SUBDIRS), $(sort $(wildcard $(citus_abs_srcdir)/$(dir)/*.c))))
 
 # be explicit about the default target
-all:
+all: citus.so
 
 # generate each version's file installation file by concatenating
 # previous upgrade scripts
Index: src/backend/distributed/executor/multi_task_tracker_executor.c
--- src/backend/distributed/executor/multi_task_tracker_executor.c.orig	2018-11-28 08:42:05.000000000 +0100
+++ src/backend/distributed/executor/multi_task_tracker_executor.c	2018-11-29 19:11:45.281763000 +0100
@@ -20,6 +20,7 @@
 #include "postgres.h"
 #include "miscadmin.h"
 
+#include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <math.h>
Index: src/backend/distributed/worker/worker_partition_protocol.c
--- src/backend/distributed/worker/worker_partition_protocol.c.orig	2018-11-28 08:42:05.000000000 +0100
+++ src/backend/distributed/worker/worker_partition_protocol.c	2018-11-29 19:11:45.282405000 +0100
@@ -18,6 +18,7 @@
 #include "funcapi.h"
 #include "pgstat.h"
 
+#include <sys/types.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <sys/stat.h>
Index: src/backend/distributed/worker/worker_sql_task_protocol.c
--- src/backend/distributed/worker/worker_sql_task_protocol.c.orig	2018-11-28 08:42:05.000000000 +0100
+++ src/backend/distributed/worker/worker_sql_task_protocol.c	2018-11-29 19:20:44.953326000 +0100
@@ -9,6 +9,8 @@
  *-------------------------------------------------------------------------
  */
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include "postgres.h"
 #include "funcapi.h"
 #include "pgstat.h"