Although GLIBC 2.15 is mentioned in the table the compiled binary contains multiple symbols from higher version:

GLIBC_2.18 __cxa_thread_atexit_impl
GLIBC_2.17 secure_getenv

The command used is: cross build --target=x86_64-unknown-linux-gnu --release
I have tried earlier docker images as well: 0.1.15, 0.1.16, 0.2.0.
When I build the project directly under a Linux VM with an earlier GLIBC version it produces a correct binary.