Header + library should either both come from the system or both from RocksDB. Also, the check only passes when the system has header+library for snappy.

Is it time to remove snappy from the RocksDB distro and always use the system versions? That would make this check easier to fix.

# Test whether Snappy library is installed
# http://code.google.com/p/snappy/
$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <snappy.h>
  int main() {}

EOF
if [ "$?" = 0 ]; then
COMMON_FLAGS="$COMMON_FLAGS -DSNAPPY"
PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS ${SNAPPY_LDFLAGS:-./snappy/libs/libsnappy.a}"
fi