Please help to find out why can't mining block 7887 of CosmosCoin(CMC)

[cosmoscoin]

Hello everyone,

Right now the mining process of CMC can't go on, it has been stucked in mining block 7887(7886 has been mined), and the CMC network has mining this block for more than 20 hours, but still can't get this block, following is the debug message, can someone help me to find out why?

If possible, please help me to check the soucecode.

Code:

7884
CosmoscoinMiner:
new block found  
  hash: 00000004a11a5a3080247c1c1c795d96e7330179d185475eaee48ed698604040  
target: 00000008359d0000000000000000000000000000000000000000000000000000
CBlock(hash=00000004a11a5a3080247c1c1c795d96e7330179d185475eaee48ed698604040, ver=4, hashPrevBlock=00000004a6598bf7e9db875c15d18ac0bb82ec6098dead3b387485bd59fbd576, hashMerkleRoot=09d9d6359ba0c1620253b2bfe63c0e1841294d6a502b0b934f7708f836fdf660, nTime=1372827390, nBits=1d08359d, nNonce=1403308544, vtx=1, vchBlockSig=3044022064838ba8efaf4fcda26d3111616e550828e0d360b299473f63dd32270036f8f602202641db4242501a1ba79881c5f09717b0b47840ca2e7ae88b9fc5a65aca54dc09)
  Coinbase(hash=09d9d6359b, nTime=1372827390, ver=1, vin.size=1, vout.size=1, nLockTime=0, strTxComment=)
    CTxIn(COutPoint(0000000000, 4294967295), coinbase 02cc1e02f700062f503253482f)
    CTxOut(nValue=3.50, scriptPubKey=036d7d566e243a707b80098e63261d8014ad250b0a59ff0009a5f943a1a2f05d5d OP_CHECKSIG)
  vMerkleTree: 09d9d6359b 
generated 3.50
AddToWallet 09d9d6359b  new
NotifyTransactionChanged 09d9d6359ba0c1620253b2bfe63c0e1841294d6a502b0b934f7708f836fdf660 status=0
updateWallet 09d9d6359ba0c1620253b2bfe63c0e1841294d6a502b0b934f7708f836fdf660 0
SetBestChain: new best=00000004a11a5a308024  height=7884  trust=7885  date=07/03/13 04:56:30,block hash= 00000004a11a5a3080247c1c1c795d96e7330179d185475eaee48ed698604040
ProcessBlock: ACCEPTED
   inWallet=1 inModel=0 Index=0-0 showTransaction=1 derivedStatus=0
   
   
   
7885
received block 000000082148a6f66e17
SetBestChain: new best=000000082148a6f66e17  height=7885  trust=7886  date=07/03/13 06:54:50,block hash= 000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0
NotifyTransactionChanged 09d9d6359ba0c1620253b2bfe63c0e1841294d6a502b0b934f7708f836fdf660 status=1
updateWallet 09d9d6359ba0c1620253b2bfe63c0e1841294d6a502b0b934f7708f836fdf660 1
   inWallet=1 inModel=1 Index=0-1 showTransaction=1 derivedStatus=1
ProcessBlock: ACCEPTED


7886
received block 000000082f31f8c70dd7
SetBestChain: new best=000000082f31f8c70dd7  height=7886  trust=7887  date=07/03/13 04:58:14,block hash= 000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205
ProcessBlock: ACCEPTED




trying 7887
CosmoscoinMiner:
new block found  
  hash: 000000001ccfcd1d3535cf66b610ebec00c22f7584075143fca244a461292688  
target: 000000004c847400000000000000000000000000000000000000000000000000
CBlock(hash=000000001ccfcd1d3535cf66b610ebec00c22f7584075143fca244a461292688, ver=4, hashPrevBlock=000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205, hashMerkleRoot=bcc950ece93fa26d421552d7b1bce67e202805109636de43b82ab6351e898edd, nTime=1372848829, nBits=1ccc8474, nNonce=3857342464, vtx=2, vchBlockSig=3045022100fbda80643e49dc83fbd77a85518be6cf995cdb26b08968258be2517f5b602d8d02200a3650a0705bcc030e13705279d7426291d195a593531dc724351f29acbdae3d)
  Coinbase(hash=5f76e4396a, nTime=1372846614, ver=1, vin.size=1, vout.size=1, nLockTime=0, strTxComment=)
    CTxIn(COutPoint(0000000000, 4294967295), coinbase 02cf1e02bf00062f503253482f)
    CTxOut(nValue=3.50, scriptPubKey=036d7d566e243a707b80098e63261d8014ad250b0a59ff0009a5f943a1a2f05d5d OP_CHECKSIG)
  CTransaction(hash=eec1452388, nTime=1372830959, ver=1, vin.size=10, vout.size=1, nLockTime=0, strTxComment=)
    CTxIn(COutPoint(b45018e2f6, 0), scriptSig=304502207213ca61f910d91a)
    CTxIn(COutPoint(32b7f14678, 0), scriptSig=304502205e2cea76de6da34c)
    CTxIn(COutPoint(6f0b98764b, 0), scriptSig=304502201e71fdb127197bcd)
    CTxIn(COutPoint(3bd01c0f4d, 0), scriptSig=304402207174d5b76688422b)
    CTxIn(COutPoint(2c906f6174, 0), scriptSig=304402200e42be1377f33276)
    CTxIn(COutPoint(b19b727915, 0), scriptSig=304502207b4c2cd53215b864)
    CTxIn(COutPoint(dc30fbf141, 0), scriptSig=3046022100c2a6bed8a1311c)
    CTxIn(COutPoint(e625ca77a8, 0), scriptSig=304602210094d81da7803997)
    CTxIn(COutPoint(f039a9dfdc, 0), scriptSig=3044022073449fecc0698427)
    CTxIn(COutPoint(b5d6c2ee98, 0), scriptSig=304402200a11791eb005bae7)
    CTxOut(nValue=35.00, scriptPubKey=OP_DUP OP_HASH160 fe095e8f8e2c4a2cb5f92de4e02084964a6d17ba OP_EQUALVERIFY OP_CHECKSIG)
  vMerkleTree: 5f76e4396a eec1452388 bcc950ece9 
generated 3.50
ERROR: CheckProofOfWork() : nBits below minimum work
ERROR: CheckBlock() : proof of work failed
ERROR: ProcessBlock() : CheckBlock FAILED
ERROR: CosmoscoinMiner : ProcessBlock, block not accepted

trying 7887
CosmoscoinMiner:
new block found  
  hash: 000000003c73bcebacaa08b78cfc90a927fc0f8249c610deb2894c14ff708853  
target: 000000004c847400000000000000000000000000000000000000000000000000
CBlock(hash=000000003c73bcebacaa08b78cfc90a927fc0f8249c610deb2894c14ff708853, ver=4, hashPrevBlock=000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205, hashMerkleRoot=c398fc119e61f31f26dc1688e41a0fbf9c9043433f6c80be7492222ae2c335b7, nTime=1372830001, nBits=1ccc8474, nNonce=1539703040, vtx=1, vchBlockSig=3045022100b4a49d56a693b9ff0992f667d1110b11eda7f5d04ee0af45b633d6e446a90fea022075a7b8b9135cae799374b9bf705562ae840f7add3a49a4c8a8b2a7fbba2c5a07)
  Coinbase(hash=c398fc119e, nTime=1372827513, ver=1, vin.size=1, vout.size=1, nLockTime=0, strTxComment=)
    CTxIn(COutPoint(0000000000, 4294967295), coinbase 02cf1e02af09062f503253482f)
    CTxOut(nValue=3.50, scriptPubKey=02922aa99f761b02d5d6f6c41552260188d6adf143f9e825f2a27c5ae03c0b72dd OP_CHECKSIG)
  vMerkleTree: c398fc119e 
generated 3.50
ERROR: CheckProofOfWork() : nBits below minimum work
ERROR: CheckBlock() : proof of work failed
ERROR: ProcessBlock() : CheckBlock FAILED
ERROR: CosmoscoinMiner : ProcessBlock, block not accepted

trying 7887
ERROR: CosmoscoinMiner : proof-of-work not meeting target

 

[cosmoscoin]

Need help from bitcoin community, it's really strange, I never met this before.

[XertroV]

Looks like your target reduced massively at block 7887, from 00000008359d00... to 000000004c847400...; ie 7 zeros to 8 zeros at the start.

Was a retarget intended for block 7887? And can you post the raw block for 7886; there might be something hiding there.

Edit:
nBits for the block you're trying to mine are nBits=1ccc8474
nBits for the previous blocks were nBits=1d08359d

Sure these are correct? This error message indicates they are not: ERROR: CheckProofOfWork() : nBits below minimum work
1ccc8474 < 1d08359d

Edit again:

Ignore most of the above, didn't realise CMC was based on PPC. There are retargets every block, so changing nBits is expected. The reason these are so drastically different is because of the algorithm used to calculate them and the leniency on block timestamps.

[JDDev]

I mined the block twice, but both were rejected.

[XertroV]

I mined the block twice, but both were rejected.

That's not the issue. The issue is that the block you're mining has the wrong nBits in the block header.

[arlington]

time stamp for block 7885 is weird, it is 2 hrs after the block 7886

[XertroV]

time stamp for block 7885 is weird, it is 2 hrs after the block 7886

Hmm.

I've got an alternate chain now:

7885: 000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0
7886: 000000061f7cee86da6458d5fbf02694db41c58e4d38aaea58606e3faefa3522
7887: 000000942feafab66ec53301532853634ccedecdc8b5fbc4fc5bebba75ba60a1
7888: 00000059bf77cf922474c474cceea4c006a58900625ac13781ede01d3aa77b34

I've mined the last 3.


Edit: fixed with this:

Try the following, I can confirm you don't download block 7887 (height 7886).

Patch main.cpp so the definition of CBlock::CheckBlock now reads:

Code:

bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot) const
{
    // These are checks that are independent of context
    // that can be verified before saving an orphan block.

    // --- patch start
    // blacklist
    if (GetHash() == uint256("0x000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205"))
        return error("CheckBlock() : hash == 000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205");
    // --- patch end

    // Size limits
    if (vtx.empty() || vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
        return DoS(100, error("CheckBlock() : size limits failed"));

Only one miner will need to implement this, to blacklist block 0x000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205, then chains should reorganize once a longer chain is produced.

No idea if this will help, but it might get you around the issue. From what I can tell you shouldn't have a difficulty adjustment at this point in time.

Didn't get to post it before it was fixed.


Update:

For posterity here is some info on the bad fork:

Code:

xertrov@x-work:~/src/cosmoscoin/src$ ./cosmoscoind getblock 000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0
{
    "hash" : "000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0",
    "confirmations" : 21,
    "size" : 266,
    "height" : 7885,
    "version" : 4,
    "merkleroot" : "2d75ef37fe8228e06a78410e6bfc6ac98bbf8e41ecf72838e754299f26243a67",
    "mint" : 3.50000000,
    "time" : 1372834490,
    "nonce" : 2004907776,
    "bits" : "1d0827a9",
    "difficulty" : 0.12262345,
    "previousblockhash" : "00000004a11a5a3080247c1c1c795d96e7330179d185475eaee48ed698604040",
    "nextblockhash" : "000000061f7cee86da6458d5fbf02694db41c58e4d38aaea58606e3faefa3522",
    "flags" : "proof-of-work",
    "proofhash" : "000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0",
    "entropybit" : 0,
    "modifier" : "bdfd70fa8e720a8b",
    "modifierchecksum" : "4e1d99b3",
    "tx" : [
        "2d75ef37fe8228e06a78410e6bfc6ac98bbf8e41ecf72838e754299f26243a67"
    ],
    "signature" : "3046022100cc37a265784beb958ad0ec0fdce5aadc92c5350bf17b08569d7b1f91536feba80221008cae649f4aa08b1b78756d74dc75d6ee30633e6abaac08a32a5f7841298c22a8"
}

xertrov@x-work:~/src/cosmoscoin/src$ ./cosmoscoind getblock 000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205
{
    "hash" : "000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205",
    "confirmations" : 0,
    "size" : 265,
    "height" : 7886,
    "version" : 4,
    "merkleroot" : "e15d62ba8b4bdf80911c4725c7b1225d4fd981359a2ae431e50918420835ffeb",
    "mint" : 0.00000000,
    "time" : 1372827494,
    "nonce" : 1900102656,
    "bits" : "1d107075",
    "difficulty" : 0.06082897,
    "previousblockhash" : "000000082148a6f66e17bab8d41af11171bc6f4d9416f983ddad0212a41775c0",
    "flags" : "proof-of-work stake-modifier",
    "proofhash" : "000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205",
    "entropybit" : 0,
    "modifier" : "a814232a8e720a8b",
    "modifierchecksum" : "f4fab8c5",
    "tx" : [
        "e15d62ba8b4bdf80911c4725c7b1225d4fd981359a2ae431e50918420835ffeb"
    ],
    "signature" : "304502204629c8a3dadc0db98ed078b34dd8cba2156e42cd65abcd173db86483745fd2f4022100987e51ae95c839254c4f7e9fc4f2164cdb4269c59775b9e28d5be34c652d77b2"
}

Does anyone want to buy 14 Cosmoscoins?

[JDDev]

Things seem to be working okay at this point. Thanks so much. If you post your CMC address, I'd love to send you some CMC.

[flyingcat]

Great, can you share how did you patch the chain? How the bad block could be attached to the chain?

[JDDev]

I believe he just updated the code as outlined above and started mining using a version based on that code, no?

[Breen2543]

Because Cosmos coin is another shit pump and dump waste of time.

[JDDev]

CMC implements quite a few innovations, first PoS coin with transaction comments. Also it has no premine

[cosmoscoin]

Looks like your target reduced massively at block 7887, from 00000008359d00... to 000000004c847400...; ie 7 zeros to 8 zeros at the start.

Was a retarget intended for block 7887? And can you post the raw block for 7886; there might be something hiding there.

Edit:
nBits for the block you're trying to mine are nBits=1ccc8474
nBits for the previous blocks were nBits=1d08359d

Sure these are correct? This error message indicates they are not: ERROR: CheckProofOfWork() : nBits below minimum work
1ccc8474 < 1d08359d

Edit again:

Ignore most of the above, didn't realise CMC was based on PPC. There are retargets every block, so changing nBits is expected. The reason these are so drastically different is because of the algorithm used to calculate them and the leniency on block timestamps.

Great thanks to you, I want to buy the bad blocks from you and I really appreciate your great help.

[cosmoscoin]

Things seem to be working okay at this point. Thanks so much. If you post your CMC address, I'd love to send you some CMC.

Great thanks to JDDev, I can send XertroV some CMC too, I mined some CMC, XertroV, please give me your CMC address and I want to buy the bad blocks from you.

[cosmoscoin]

CMC implements quite a few innovations, first PoS coin with transaction comments. Also it has no premine

Correct answer.

[Breen2543]

CMC implements quite a few innovations, first PoS coin with transaction comments. Also it has no premine

lol, thats all? Really.....  wait, yup, just as I thought, this post is full of noobs...

 Have fun with your novelty cosmo coin kids. Youll learn someday.

[JDDev]

Ok, as you have PXC in your sig, what innovation did PXC add? Nothing, and on top of that had a huge premine.

[XertroV]

Great thanks to you, I want to buy the bad blocks from you and I really appreciate your great help.

I didn't mine any 'bad' blocks; there was only one which was on the end of the chain.

You're welcome , it wasn't a huge deal though, and I didn't actually figure out the problem, just work around it.

If you'd like to send me some CMC you can here: C72cU8HH6ryHSScDqMymtYYxu5kEWjN9bx

Great, can you share how did you patch the chain? How the bad block could be attached to the chain?

I believe he just updated the code as outlined above and started mining using a version based on that code, no?

This is correct. The patch itself was:

Code:

if (GetHash() == uint256("0x000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205"))
    return error("CheckBlock() : hash == 000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205");

Basically it would just fail if you tried to add block 0x000000082f31f... to the main chain, allowing me to mine from the previous block and create an alternate chain which took precedence when it became longer. Then the rest of the network took over and there were like 200 blocks in 2 minutes (the difficulty was low because it recalcs for every block).

JDDev and cosmoscoin, not sure if either or both of you are developing this, but your block target and retarget time are low enough that you might get problems. I'm not certain that is what allowed the 7886 block; the PoS aspect might have had quite a bit to do with it. In any case, there's evidently a bug that needs to be worked out.

[cosmoscoin]

CMC implements quite a few innovations, first PoS coin with transaction comments. Also it has no premine

lol, thats all? Really.....  wait, yup, just as I thought, this post is full of noobs...

 Have fun with your novelty cosmo coin kids. Youll learn someday.

I respect your opinion, but we are working on CMC and try to make it a good coin for the community, although CMC doesn't have many innovations, but it's the most functional coin in the community right now.

[cosmoscoin]

Great thanks to you, I want to buy the bad blocks from you and I really appreciate your great help.

I didn't mine any 'bad' blocks; there was only one which was on the end of the chain.

You're welcome , it wasn't a huge deal though, and I didn't actually figure out the problem, just work around it.

If you'd like to send me some CMC you can here: C72cU8HH6ryHSScDqMymtYYxu5kEWjN9bx

Great, can you share how did you patch the chain? How the bad block could be attached to the chain?

I believe he just updated the code as outlined above and started mining using a version based on that code, no?

This is correct. The patch itself was:

Code:

if (GetHash() == uint256("0x000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205"))
    return error("CheckBlock() : hash == 000000082f31f8c70dd7f9a857f04fe14f7df2a57bb9bc1f54d336c70dea6205");

Basically it would just fail if you tried to add block 0x000000082f31f... to the main chain, allowing me to mine from the previous block and create an alternate chain which took precedence when it became longer. Then the rest of the network took over and there were like 200 blocks in 2 minutes (the difficulty was low because it recalcs for every block).

JDDev and cosmoscoin, not sure if either or both of you are developing this, but your block target and retarget time are low enough that you might get problems. I'm not certain that is what allowed the 7886 block; the PoS aspect might have had quite a bit to do with it. In any case, there's evidently a bug that needs to be worked out.

Because CMC doesn't have premine, and I don't have many CMC, I can send you 100 CMC, thanks again.