On OSX 10.10.1,

With the small_example, and with python 3.4.3 and:
$ export CXX="env BAR=FOO g++"
$ python3 setup.py build_ext build install --prefix=`pwd`
running build_ext
building '_example' extension
swigging example/example.i to example/example_wrap.cpp
swig -python -c++ -py3 -Iexample -o example/example_wrap.cpp example/example.i
creating build
creating build/temp.macosx-10.10-x86_64-3.4
creating build/temp.macosx-10.10-x86_64-3.4/example
gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Iexample -I/Users/jjc/bug/py343/include/python3.4m -c example/example_wrap.cpp -o build/temp.macosx-10.10-x86_64-3.4/example/example_wrap.o
gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Iexample -I/Users/jjc/bug/py343/include/python3.4m -c example/example.cxx -o build/temp.macosx-10.10-x86_64-3.4/example/example.o
creating build/lib.macosx-10.10-x86_64-3.4
creating build/lib.macosx-10.10-x86_64-3.4/example
env -bundle -undefined dynamic_lookup build/temp.macosx-10.10-x86_64-3.4/example/example_wrap.o build/temp.macosx-10.10-x86_64-3.4/example/example.o -o build/lib.macosx-10.10-x86_64-3.4/example/_example.so
env: illegal option -- b
usage: env [-i] [name=value ...] [utility [argument ...]]
error: command 'env' failed with exit status 1


So, as is, python 3.4.3 fails.

With the same as above, but with the fix-distutils-342.patch applied:
$ export CXX="env BAR=FOO g++"
$ python3 setup.py build_ext build install --prefix=`pwd`
running build_ext
building '_example' extension
swigging example/example.i to example/example_wrap.cpp
swig -python -c++ -py3 -Iexample -o example/example_wrap.cpp example/example.i
creating build
creating build/temp.macosx-10.10-x86_64-3.4
creating build/temp.macosx-10.10-x86_64-3.4/example
gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Iexample -I/Users/jjc/bug/py343m/include/python3.4m -c example/example_wrap.cpp -o build/temp.macosx-10.10-x86_64-3.4/example/example_wrap.o
gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Iexample -I/Users/jjc/bug/py343m/include/python3.4m -c example/example.cxx -o build/temp.macosx-10.10-x86_64-3.4/example/example.o
creating build/lib.macosx-10.10-x86_64-3.4
creating build/lib.macosx-10.10-x86_64-3.4/example
gcc -bundle -undefined dynamic_lookup build/temp.macosx-10.10-x86_64-3.4/example/example_wrap.o build/temp.macosx-10.10-x86_64-3.4/example/example.o -o build/lib.macosx-10.10-x86_64-3.4/example/_example.so
running build
running build_py
copying example/example.py -> build/lib.macosx-10.10-x86_64-3.4/example
copying example/__init__.py -> build/lib.macosx-10.10-x86_64-3.4/example
running install
running install_lib
creating /Users/jjc/bug/small_example/lib
creating /Users/jjc/bug/small_example/lib/python3.4
creating /Users/jjc/bug/small_example/lib/python3.4/site-packages
creating /Users/jjc/bug/small_example/lib/python3.4/site-packages/example
copying build/lib.macosx-10.10-x86_64-3.4/example/__init__.py -> /Users/jjc/bug/small_example/lib/python3.4/site-packages/example
copying build/lib.macosx-10.10-x86_64-3.4/example/_example.so -> /Users/jjc/bug/small_example/lib/python3.4/site-packages/example
copying build/lib.macosx-10.10-x86_64-3.4/example/example.py -> /Users/jjc/bug/small_example/lib/python3.4/site-packages/example
byte-compiling /Users/jjc/bug/small_example/lib/python3.4/site-packages/example/__init__.py to __init__.cpython-34.pyc
byte-compiling /Users/jjc/bug/small_example/lib/python3.4/site-packages/example/example.py to example.cpython-34.pyc
running install_egg_info
Writing /Users/jjc/bug/small_example/lib/python3.4/site-packages/example-0.5-py3.4.egg-info
$ export PYTHONPATH=`pwd`/lib/python3.4/site-packages
$ cd test
$ python3 a_test.py 
3


So with the patch, it succeeds.  

> Does the patch fix things on Mac OS X and Linux?
Yes.