The error was:

util/logging.cc: In function 'int rocksdb::AppendHumanMicros(uint64_t, char*, int)':
error: util/logging.cc:41:39: integer overflow in expression [-Werror=overflow]
} else if (micros < 1000000l * 60 * 60) {
^
error: util/logging.cc:41:39: comparison between signed and unsigned integer expressions [-Werror=sign-compare]