9.3.5 failing to compile with dtrace on FreeBSD 10.1

Hi all,
I'm trying to compile 9.3.5 from ports on FreeBSD 10.1-release with
dtrace enabled.
It was a long time ago I looked at dtrace + PostgreSQL + FreeBSD (see
[1], [2]), so I'm not updated on how far it got.
The problem I have in compilation is as follows:

gmake[2]: Entering directory
'/mnt/ada1a/ports/databases/postgresql93-server/work/postgresql-9.3.5/src/backend'
gmake -C utils probes.h
gmake[3]: Entering directory
'/mnt/ada1a/ports/databases/postgresql93-server/work/postgresql-9.3.5/src/backend/utils'
dtrace -C -h -s probes.d -o probes.h.tmp
dtrace: failed to compile script probes.d: "/usr/lib/dtrace/ip.d",
line 2: type redeclared: struct devinfo
Makefile:38: recipe for target 'probes.h' failed
gmake[3]: *** [probes.h] Error 1
gmake[3]: Leaving directory
'/mnt/ada1a/ports/databases/postgresql93-server/work/postgresql-9.3.5/src/backend/utils'
Makefile:157: recipe for target 'utils/probes.h' failed
gmake[2]: *** [utils/probes.h] Error 2
gmake[2]: Leaving directory
'/mnt/ada1a/ports/databases/postgresql93-server/work/postgresql-9.3.5/src/backend'
*** Error code 2

Am I missing something?

Thanks,
Luca

[1] http://www.postgresql.org/message-id/28743.1301771552@sss.pgh.pa.us
[2] https://forums.freebsd.org/threads/dtrace-userland-and-postgresql.22914/#post-129378