Compilation Error on MacOS High Sierra

Dear pyql developers,

I am experiencing the following compilation error on my platform:
----------------------------------------------------------------
quantlib/time/date.cpp:1722:80: error: no type named 'Hour' in namespace
'QuantLib'
...PyObject* __Pyx_PyInt_From_QuantLib_3a__3a_Hour(QuantLib::Hour value);
~~~~~~~~~~^
quantlib/time/date.cpp:1725:82: error: no type named 'Minute' in namespace
'QuantLib'
...PyObject* __Pyx_PyInt_From_QuantLib_3a__3a_Minute(QuantLib::Minute value);
~~~~~~~~~~^
quantlib/time/date.cpp:1728:82: error: no type named 'Second' in namespace
'QuantLib'
...PyObject* __Pyx_PyInt_From_QuantLib_3a__3a_Second(QuantLib::Second value);
~~~~~~~~~~^
quantlib/time/date.cpp:1731:87: error: no type named 'Millisecond' in namespace
'QuantLib'
...PyObject* __Pyx_PyInt_From_QuantLib_3a__3a_Millisecond(QuantLib::Millise...
~~~~~~~~~~^
quantlib/time/date.cpp:1734:87: error: no type named 'Microsecond' in namespace
'QuantLib'
...PyObject* __Pyx_PyInt_From_QuantLib_3a__3a_Microsecond(QuantLib::Microse...
~~~~~~~~~~^
quantlib/time/date.cpp:1758:32: error: no type named 'Hour' in namespace
'QuantLib'
static CYTHON_INLINE QuantLib::Hour __Pyx_PyInt_As_QuantLib_3a__3a_Hour(...
~~~~~~~~~~^
quantlib/time/date.cpp:1761:32: error: no type named 'Minute' in namespace
'QuantLib'
static CYTHON_INLINE QuantLib::Minute __Pyx_PyInt_As_QuantLib_3a__3a_Min...
~~~~~~~~~~^
quantlib/time/date.cpp:1764:32: error: no type named 'Second' in namespace
'QuantLib'
static CYTHON_INLINE QuantLib::Second __Pyx_PyInt_As_QuantLib_3a__3a_Sec...
~~~~~~~~~~^
quantlib/time/date.cpp:1767:32: error: no type named 'Millisecond' in namespace
'QuantLib'
static CYTHON_INLINE QuantLib::Millisecond __Pyx_PyInt_As_QuantLib_3a__3...
~~~~~~~~~~^
quantlib/time/date.cpp:1770:32: error: no type named 'Microsecond' in namespace
'QuantLib'
static CYTHON_INLINE QuantLib::Microsecond __Pyx_PyInt_As_QuantLib_3a__3...
~~~~~~~~~~^
quantlib/time/date.cpp:5119:13: error: no type named 'Hour' in namespace
'QuantLib'
QuantLib::Hour __pyx_t_17;
~~~~~~~~~~^
quantlib/time/date.cpp:5120:13: error: no type named 'Minute' in namespace
'QuantLib'
QuantLib::Minute __pyx_t_18;
~~~~~~~~~~^
quantlib/time/date.cpp:5121:13: error: no type named 'Second' in namespace
'QuantLib'
QuantLib::Second __pyx_t_19;
~~~~~~~~~~^
quantlib/time/date.cpp:5123:13: error: no type named 'Millisecond' in namespace
'QuantLib'
QuantLib::Millisecond __pyx_t_21;
~~~~~~~~~~^
quantlib/time/date.cpp:5125:13: error: no type named 'Microsecond' in namespace
'QuantLib'
QuantLib::Microsecond __pyx_t_23;
~~~~~~~~~~^
quantlib/time/date.cpp:5438:110: error: no member named 'Hour' in namespace
'QuantLib'; did you mean 'Hours'?
...if (unlikely((__pyx_t_17 == ((QuantLib::Hour)-1)) && PyErr_Occurred())) ...
~~~~~~~~~~^~~~
Hours
quantlib/time/date.cpp:823:43: note: expanded from macro 'unlikely'
#define unlikely(x) __builtin_expect(!!(x), 0)
^
/usr/local/include/ql/time/timeunit.hpp:41:21: note: 'Hours' declared here
Hours,
^
quantlib/time/date.cpp:5439:114: error: no member named 'Minute' in namespace
'QuantLib'; did you mean 'Minutes'?
...if (unlikely((__pyx_t_18 == ((QuantLib::Minute)-1)) && PyErr_Occurred())...
~~~~~~~~~~^~~~~~
Minutes
quantlib/time/date.cpp:823:43: note: expanded from macro 'unlikely'
#define unlikely(x) __builtin_expect(!!(x), 0)
^
/usr/local/include/ql/time/timeunit.hpp:42:21: note: 'Minutes' declared here
Minutes,
^
quantlib/time/date.cpp:5440:114: error: no member named 'Second' in namespace
'QuantLib'; did you mean 'Seconds'?
...if (unlikely((__pyx_t_19 == ((QuantLib::Second)-1)) && PyErr_Occurred())...
~~~~~~~~~~^~~~~~
Seconds
quantlib/time/date.cpp:823:43: note: expanded from macro 'unlikely'
#define unlikely(x) __builtin_expect(!!(x), 0)
^
/usr/local/include/ql/time/timeunit.hpp:43:21: note: 'Seconds' declared here
Seconds,
^
quantlib/time/date.cpp:5449:162: error: expected ')'
...((QuantLib::Year)__pyx_t_8), ((QuantLib::Hour)__pyx_t_17), ((QuantLib::M...
^
quantlib/time/date.cpp:5449:145: note: to match this '('
...((enum QuantLib::Month)__pyx_t_7), ((QuantLib::Year)__pyx_t_8), ((QuantL...
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
error: command 'gcc' failed with exit status 1
make: *** [build3] Error 1
----------------------------------------------------------------
I am using quantlib 1.12 and boost 1.66 installed via homebrew and Python 3.6.5. via Anaconda.
GCC is Apple LLVM version 9.1.0 (clang-902.0.39.1).

Your help is very much appreciated!

Thank you,

Michael