Failed to find shared library for backend ”mysql

编译好sql_db_plugin后启动nodeos

root@iZ2zea5mjpcmz9m17k56daZ:/home/surou/Documents/github/eos/build# nodeos --sql_db-uri=”mysql://db=eos user=root host=127.0.0.1 password='数据库密码' --sql_db-block-start=0  --delete-all-blocks
2018-07-25T12:39:28.628 thread-0   sql_db_plugin.cpp:81          set_program_options  ] set_program_options
2018-07-25T12:39:28.629 thread-0   chain_plugin.cpp:271          plugin_initialize    ] initializing chain plugin
2018-07-25T12:39:28.629 thread-0   chain_plugin.cpp:408          plugin_initialize    ] Deleting state database and blocks
2018-07-25T12:39:28.721 thread-0   chain_plugin.cpp:508          plugin_initialize    ] Starting up fresh blockchain with default genesis state.
2018-07-25T12:39:29.437 thread-0   http_plugin.cpp:344           plugin_initialize    ] configured http to listen on 127.0.0.1:8888
2018-07-25T12:39:29.437 thread-0   net_plugin.cpp:2941           plugin_initialize    ] Initialize net plugin
2018-07-25T12:39:29.437 thread-0   net_plugin.cpp:2966           plugin_initialize    ] host: 0.0.0.0 port: 9876 
2018-07-25T12:39:29.437 thread-0   net_plugin.cpp:3036           plugin_initialize    ] my node_id is e5f1d9687a24d343c57e7ba32913db448147a2e9e7dc1fe12797a69c082e1c9a
2018-07-25T12:39:29.437 thread-0   wallet_plugin.cpp:42          plugin_initialize    ] initializing wallet plugin
2018-07-25T12:39:29.437 thread-0   sql_db_plugin.cpp:96          plugin_initialize    ] initialize
2018-07-25T12:39:29.437 thread-0   sql_db_plugin.cpp:104         plugin_initialize    ] connecting to ”mysql://db=eos
2018-07-25T12:39:29.438 thread-0   main.cpp:141                  main                 ] Failed to find shared library for backend ”mysql

报Failed to find shared library for backend ”mysql 错误。
查看EOS代码 eos\programs\nodeos\main.cpp:141

   } catch( const std::runtime_error& e ) {
      if( std::string(e.what()) == "database dirty flag set" ) {
         elog( "database dirty flag set (likely due to unclean shutdown): replay required" );
         return DATABASE_DIRTY;
      } else if( std::string(e.what()) == "database metadata dirty flag set" ) {
         elog( "database metadata dirty flag set (likely due to unclean shutdown): replay required" );
         return DATABASE_DIRTY;
      } else {
         elog( "${e}", ("e",e.what())); // :141
      }
      return OTHER_FAIL;
   } catch( const std::exception& e ) {

应该出在sql_db_plugin中的soci连接中
下载soci源代码

git clone https://github.com/SOCI/soci.git

查看错误出现在

// non-synchronized helper
void do_register_backend(std::string const & name, std::string const & shared_object)
{
    // The rules for backend search are as follows:
    // - if the shared_object is given,
    //   it names the library file and the search paths are not used
    // - otherwise (shared_object not provided or empty):
    //   - file named libsoci_NAME.so.SOVERSION is searched in the list of search paths

    soci_handler_t h = 0;
    if (shared_object.empty() == false)
    {
        h = DLOPEN(shared_object.c_str());
    }
    else
    {
        // try system paths
        h = DLOPEN(LIBNAME(name).c_str());
        if (0 == h)
        {
            // try all search paths
            for (std::size_t i = 0; i != search_paths_.size(); ++i)
            {
                std::string const fullFileName(search_paths_[i] + "/" + LIBNAME(name));
                h = DLOPEN(fullFileName.c_str());
                if (0 != h)
                {
                    // already found
                    break;
                }
             }
         }
    }

    if (0 == h)
    {
        throw soci_error("Failed to find shared library for backend " + name);
    }

发现刚才出现此问题是因为输入的参数符号错误导致，问题停止跟进，以后在遇到类似的再跟进....