forward portability

[paul zimmermann]

       Dear Szabolcs,

> try CC='gcc -no-pie' ?

thank you, this did the trick. I was able to compile all releases of glibc
back to 2.14 (June 2011)!

For 2.13 it seems more difficult according to [1], thus I'll stop there:

/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/libselinux.so: undefined reference to `memcpy@GLIBC_2.14'

Best regards,
Paul

[1] https://stackoverflow.com/questions/12286460/undefined-reference-to-mempcyglibc-2-14-when-compiling-on-linux