I believe the error: File exists is just from running setup.py build twice. You can remove the build/ directory to get a clean build.
The GLIBC_2.14 not found issue is not related to that. Your version of RHEL is unfortunately too old. It's similar to the GLIBCXX issue mentioned under Troubleshooting. According to the Online Help, the oldest platform that Extract API 2 targets is CentOS 7 (or equivalent), and that comes with GLIBC version 2.17.
If upgrading is no option, I'm not aware of an easy solution. One way would be to put a separate version of glibc 2.17 on the host and then, before launching Python, use things like LD_LIBRARY_PATH or chroot to point the runtime loader to it. But that's a rather involved method, such a GLIBC installation consists of 100s of little pieces.