Hermes log module is unrecognized by client command line

Even though the code is available, enabling it through LIBGKFS_LOG=hermes produces the following output:

[amiranda@host: ~] $ LD_LIBRARY_PATH=~/var/projects/gekkofs/prefix/lib/ LD_PRELOAD=~/var/projects/gekkofs/prefix/lib/libgkfs_intercept.so LIBGKFS_LOG=hermes LIBGKFS_LOG_SYSCALL_FILTER=epoll_wait LIBGKFS_LOG_OUTPUT=/dev/stderr LIBGKFS_LOG_DEBUG_VERBOSITY=1 ~/var/projects/gekkofs/source/test/build/gkfs_test_dir
warning: logging option 'hermes' unknown; try LIBGKFS_LOG=help