When enabling dtrace support via the --with-dtrace configure flag, build fails on FreeBSD with this message:

/usr/sbin/dtrace  -o Include/pydtrace_probes.h -h -s
dtrace: option requires an argument -- s

Looks like line 882 of Makefile.pre.in:

    882         $(DTRACE) $(DFLAGS) -o $@ -h -s $<

changing this to:

    882         $(DTRACE) $(DFLAGS) -o $@ -h -s $(srcdir)/Include/pydtrace.d

avoids that issue. Note that bmake is being used here.

After this however, another issue is encountered during linking:

Python/ceval.o: In function `_PyEval_EvalFrameDefault':
Python/ceval.c:(.text+0xc94): undefined reference to `__dtraceenabled_python___function__entry'
Python/ceval.c:(.text+0xcdd): undefined reference to `__dtrace_python___function__entry'
Python/ceval.c:(.text+0xff0): undefined reference to `__dtraceenabled_python___line'
Python/ceval.c:(.text+0x109f): undefined reference to `__dtrace_python___line'
Python/ceval.c:(.text+0x125e): undefined reference to `__dtraceenabled_python___line'
Python/ceval.c:(.text+0x12e5): undefined reference to `__dtraceenabled_python___line'
Python/ceval.c:(.text+0x1358): undefined reference to `__dtraceenabled_python___line'
Python/ceval.c:(.text+0x13f2): undefined reference to `__dtraceenabled_python___line'
Python/ceval.c:(.text+0x146c): undefined reference to `__dtraceenabled_python___line'
Python/ceval.o:Python/ceval.c:(.text+0x14de): more undefined references to `__dtraceenabled_python___line' follow
Python/ceval.o: In function `_PyEval_EvalFrameDefault':
Python/ceval.c:(.text+0x87f2): undefined reference to `__dtraceenabled_python___function__return'
Python/ceval.c:(.text+0x8833): undefined reference to `__dtrace_python___function__return'
Modules/gcmodule.o: In function `collect':
Modules/gcmodule.c:(.text+0x380): undefined reference to `__dtraceenabled_python___gc__start'
Modules/gcmodule.c:(.text+0x38c): undefined reference to `__dtrace_python___gc__start'
Modules/gcmodule.c:(.text+0xe1b): undefined reference to `__dtraceenabled_python___gc__done'
Modules/gcmodule.c:(.text+0xe2a): undefined reference to `__dtrace_python___gc__done'

which I believe is due to dtrace -G modifying Python/ceval.o and Modules/gcmodule.o. 

Finally, note that all calls to dtrace -G or dtrace -h on FreeBSD 11.0 should have -xnolibs added to enable use without the DTrace kernel modules loaded. Otherwise dtrace processes the /usr/lib/dtrace scripts unnecessarily, and errors out when it tries to talk to the DTrace kernel code, causing build failure in a jail.

(I can provide patches, but suspect you have preferences about how the build system work that I'm not aware of, so wanted to explain before patching in ways that aren't satisfactory.)

I cannot repro as I don't have a FreeBSD environment handy. I will gladly accept a patch that makes it work with FreeBSD 11.0!

I admit I tested my implementation with OS X 10.11 and Linux (SystemTap with Ubuntu).

For what it's worth, the koobs-freebsd-current buildbot worker has DTrace enabled and can be used to build/test Python/dtrace bits

Zach and I spoke recently about getting custom builds hooked up to GitHub, which I believe is now already possible, so all that's left is to determine a way to pass the appropriate extra configure argument to the build without having to create another customer builder. CC Zach accordingly

Patch for the FreeBSD Ports to fix the build failure: https://reviews.freebsd.org/D31489