恐慌：运行时错误：运行Blockchainr时无效的内存地址或零指针取消引用

Question

我运行blockchainr并获得以下终端输出：17:39:57 2015-06-16 [INF] loading db leveldbpanic: runtime error: invalid memory address or nil pointer dereference    panic: runtime error: invalid memory address or nil pointer dereference[signal 0xb code=0x1 addr=0x0 pc=0x402cb63]goroutine 1 [running]:main.search(0x4911ef8, 0xc20806e2d0, 0x0, 0x0, 0x4911ef8)    /Users/mesquka/Downloads/blockchainr-master/src/blockchainr/main.go:185 +0x3famain.main()    /Users/mesquka/Downloads/blockchainr-master/src/blockchainr/main.go:284 +0x3cegoroutine 5 [semacquire]:sync.(*Cond).Wait(0xc208045100)    /usr/local/go/src/sync/cond.go:62 +0x9egithub.com/conformal/seelog.(*asyncLoopLogger).processItem(0xc20802c4e0, 0x0)    /Users/mesquka/Downloads/blockchainr-master/src/github.com/conformal/seelog/behavior_asynclooplogger.go:50 +0xc2github.com/conformal/seelog.(*asyncLoopLogger).processQueue(0xc20802c4e0)    /Users/mesquka/Downloads/blockchainr-master/src/github.com/conformal/seelog/behavior_asynclooplogger.go:63 +0x31created by github.com/conformal/seelog.newAsyncLoopLogger    /Users/mesquka/Downloads/blockchainr-master/src/github.com/conformal/seelog/behavior_asynclooplogger.go:40 +0x8e代码位于https://github.com/FiloSottile/blockchainr我运行的特定命令（按顺序）是：使所有./bin/btcd --datadir=~/Btcd/./bin/blockchainr -datadir ~/Btcd/最后一个命令是我得到这个终端输出的地方。

Answer 1

您的问题在于Blockchainr main.go以下几行：

var (

    dataDir = flag.String("datadir", filepath.Join(btcutil.AppDataDir("btcd", false), "data"), "BTCD: Data directory")

    dbType  = flag.String("dbtype", "leveldb", "BTCD: Database backend")

)

如您所见，如果您不指定dbtype默认标志，则"leveldb"它希望datadir参数包含 LevelDB 数据库的路径。