Description of problem:
Boost doesn't build --without python3


Proposed fix

diff -up boost/boost.spec.old boost/boost.spec
--- boost/boost.spec.old	2012-05-24 11:29:55.083758818 +0200
+++ boost/boost.spec	2012-05-24 11:30:11.761633553 +0200
@@ -687,7 +687,9 @@ export PATH=/bin${PATH:+:}$PATH
 %endif
 
 echo ============================= install Python 3 ==================
+%if %{with python3}
 DESTDIR=$RPM_BUILD_ROOT make -C serial-python3 VERBOSE=1 install
+%endif
 
 echo ============================= install serial ==================
 DESTDIR=$RPM_BUILD_ROOT make -C serial VERBOSE=1 install