Index: head/sysutils/apache-mesos/Makefile
===================================================================
--- head/sysutils/apache-mesos/Makefile
+++ head/sysutils/apache-mesos/Makefile
@@ -2,7 +2,7 @@
 
 PORTNAME=	mesos
 PORTVERSION=	1.9.0
-PORTREVISION=	4
+PORTREVISION=	5
 CATEGORIES=	sysutils
 MASTER_SITES=	APACHE/mesos/${PORTVERSION}
 PKGNAMEPREFIX=	apache-
Index: head/sysutils/apache-mesos/files/patch-3rdparty_stout_include_stout_os_freebsd.hpp
===================================================================
--- head/sysutils/apache-mesos/files/patch-3rdparty_stout_include_stout_os_freebsd.hpp
+++ head/sysutils/apache-mesos/files/patch-3rdparty_stout_include_stout_os_freebsd.hpp
@@ -0,0 +1,49 @@
+--- 3rdparty/stout/include/stout/os/freebsd.hpp.orig	2020-05-22 20:48:06 UTC
++++ 3rdparty/stout/include/stout/os/freebsd.hpp
+@@ -88,18 +88,29 @@ inline Try<Memory> memory()
+   const size_t pageSize = os::pagesize();
+ 
+   unsigned int freeCount;
+-  size_t length = sizeof(freeCount);
+-
++  size_t freeCountLength = sizeof(freeCount);
+   if (sysctlbyname(
+-      "vm.stats.v_free_count",
++      "vm.stats.vm.v_free_count",
+       &freeCount,
+-      &length,
++      &freeCountLength,
+       nullptr,
+       0) != 0) {
+     return ErrnoError();
+   }
+-  memory.free = Bytes(freeCount * pageSize);
+ 
++  unsigned int inactiveCount;
++  size_t inactiveCountLength = sizeof(inactiveCount);
++  if (sysctlbyname(
++      "vm.stats.vm.v_inactive_count",
++      &inactiveCount,
++      &inactiveCountLength,
++      nullptr,
++      0) != 0) {
++    return ErrnoError();
++  }
++
++  memory.free = Bytes((freeCount + inactiveCount) * pageSize);
++
+   int totalBlocks = 0;
+   int usedBlocks = 0;
+ 
+@@ -112,8 +123,9 @@ inline Try<Memory> memory()
+   // FreeBSD supports multiple swap devices. Here we sum across all of them.
+   struct xswdev xswd;
+   size_t xswdSize = sizeof(xswd);
+-  int* mibDevice = &(mib[mibSize + 1]);
+-  for (*mibDevice = 0; ; (*mibDevice)++) {
++  for (int ndev = 0; ; ndev++) {
++      mib[mibSize] = ndev;
++
+       if (::sysctl(mib, 3, &xswd, &xswdSize, nullptr, 0) != 0) {
+           if (errno == ENOENT) {
+               break;