[MapProxy] How to install on virtualenv?

[Kazuhiro Niitsuma]

Hi all,
I have a CentOS6.3(64bit) on VMWare and I want to run MapProxy on this
system but now I'm facing some troubles for instlation.

First time I installed MapProxy on CentOS6.3 without virtualenv, no troubles
has met.

But next time I installed MapProxy on vurtualenv, which is recommended to
run MapProxy on it, instlation has failed.
This time what I did was:
1. mkdir mapenv
->done.
2. virtualenv mapenv
->done.
3. source mapenv/bin/activate
->done.
4. pip install PyYAML
->done.
5. pip install MapProxy
->failed.
So many compilation errors ware detected in _imaging.c .

What should I do to install MapProxy on virtualenv on CentOS6.3?
Any comments will be welcome.

Best Regards,
-- 
Kazuhiro Niitsuma