Sorry, I don't see where you have shown exactly what Python ./configure and make commands you are using and it is not at all obvious to me what you mean by "After generating Makefile if comment string, contain LD_CONFIG_PATH all build success".  But, if it is the case that you are using Gentoo tools to build ("python version 2.7.8 from ebuild") then perhaps you should be asking on a Gentoo forum as we have no control or specific knowledge of how Gentoo packages things.  If you can show exactly how a Python build fails using an unpacked Python source package, the Python's ./configure and make, then we can investigate.  In other words, we would need to see the exact sequence of the exact commands you use.  There are just too many variables to try to guess what you might be seeing (other than my original speculation about Issue21166).  Did you try the recommendations above in msg227011?