I have some problem to build numpy with the Software Collection environment

at the binary build stage I got this error

# rpmbuild -bb numpy.spec --define 'scl python27' --define 'scl_prefix
python27-'
[ ... ]
+ /usr/lib/rpm/brp-scl-python-bytecompile
/opt/rh/python27/root/usr/bin/python 1 /opt/rh/python27/root
Bytecompiling .py files below
/home/foo/rpms/BUILDROOT/python27-numpy-1.7.1-8.el6.x86_64//opt/rh/python27/root/usr/lib64/python2.7/
using /usr/bin/python2.7
/usr/lib/rpm/brp-scl-python-bytecompile: line 47: /usr/bin/python2.7: No
such file or directory

and it should be
+ scl enable python27
'/usr/lib/rpm/redhat/brp-python-bytecompile-with-scl-python
/opt/rh/python27/root/usr/bin/python2 1 /opt/rh/python27/root'

thanks
Fabrice