py-bob-ip-base: build fails on 10.8, error: use of undeclared identifier 'isnan'

[dbevans (David B. Evans)]

:info:build /usr/bin/clang -DNDEBUG -g -fwrapv -O3 -Wall -arch x86_64 -Wno-strict-aliasing -DBOB_EXT_MODULE_PREFIX="bob.ip.base" -DBOB_EXT_MODULE_NAME="_library" -DBOB_EXT_ENTRY_NAME=init_library -DBOB_EXT_MODULE_VERSION="2.0.7" -DHAVE_BOOST=1 -DBOOST_VERSION="1.59.0" -DHAVE_BLITZ=1 -DBLITZ_VERSION="0.10" -DHAVE_VLFEAT=1 -DPY_ARRAY_UNIQUE_SYMBOL=BOB_NUMPY_C_API -DNO_IMPORT_ARRAY=1 -DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION -I/opt/local/var/macports/build/_Volumes_MiniHD_opt_macports_trunk_dports_python_py-bob-ip-base/py27-bob-ip-base/work/bob.ip.base-2.0.7/bob/ip/base/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/blitz/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/extension/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/io/base/include -I/opt/local/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/sp/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/math/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/bob/core/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c bob/ip/base/affine.cpp -o build/temp.macosx-10.8-x86_64-2.7/bob/ip/base/affine.o -std=c++0x -Wno-#warnings -isystem /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/core/include -isystem /opt/local/include -isystem /opt/local/lib
:info:build bob/ip/base/affine.cpp:134:8: error: use of undeclared identifier 'isnan'; did you mean 'blitz::isnan'?
:info:build   if (!isnan(scale_factor)){
:info:build        ^~~~~
:info:build        blitz::isnan
:info:build /usr/include/c++/4.2.1/cmath:551:5: note: 'blitz::isnan' declared here
:info:build     isnan(_Tp __f) { return ::__gnu_cxx::__capture_isnan(__f); }
:info:build     ^
:info:build 1 error generated.

[dbevans (David B. Evans)]

Build log showing failure

[mf2k (Frank Schima)]

See #56287.