Ok, this is great info. But why is the segwit data only attached to coinbase transactions? Of the the random picks of transactions I've checked, this is true.
Edit: Sorry, read the above post again and got it this time. Thanks for your answers.

Ok, great. But my regtest setup (version 14.1) gives me a similar raw coinbase transaction:
Is the implementation error in the node? Maybe working in 15.0?

My node is a couple of days of synching behind, so I can't get the transaction from it yet. But I tried getting the raw transaction from electrum wallet and chainquery.com, and they all have the long tail starting with 12... Where did you get your raw transaction?

Thanks. That's really strange. I'm getting the raw transaction from https://blockchain.info/tx/d0783f480343fb37b009b5e3db90ccad85e2c8314639de98b3bb66c396dd7915?format=hex , I haven't tried getting the data from my node, since I'm currently running tests in regtest mode. By the way, I'm having this problem in regtest aswell. I'll look more into this when I get home from work.

I'm not able to get a txid from coinbase transactions, by hashing. I can get it from any other transaction by doing the double hash. Here's what I'm trying:

Output when using a normal transaction:

Output when using a coinbase transaction:

I haven't been able to find any documentation about this. Does anybody know why this is?

Well, there is some documentation, but it doesn't answer my question.. https://media.readthedocs.org/pdf/python-bitcoinlib/latest/python-bitcoinlib.pdf . I was rather hoping that one of the developers would read this forum. Im reading the source code, but its kind of difficult to follow with the high level of abstraction (at least with my experiencie in mostly simple python code).

BTW is this the correct subforum for this post? I can't really find one that seems to fit the question, but i read that this subforum is not for support inquiries.

I'm trying to learn about bitcoin by writing a python bitcoin miner using python-bitcoinlib (https://github.com/petertodd/python-bitcoinlib).
I'm having problems creating a complete CBlock with data from a getblocktemplate request. I get all parameters right except from the transactions, the vtx() in the function argument. CBlock() accepts an array of CTransaction()-objects. Is this the correct parameter? If so, how do I populate add data to the CTransaction()-objects from the getblocktemplate data? I've tried using the template transaction-data, but I only get errors of the type:  AttributeError: 'unicode' object has no attribute 'read'. I tried formatting the data as string or int aswell. What kind of object should be passed to CTransaction()? I'm reading the source code, but I can't figure it out.

No error:

Error:
gives

So, am I submitting the right data but in wrong format (how do I make data a serializable object?) or is the data wrong all together?