I created a transaction in Go, signed it with a EIP155Signer signer, but when I try to publish the transaction through the Go client to the private blockchain, I get the error Invalid sender. Any idea what's happening here? Frustrated by this.

This issue seems to have the same error: https://github.com/ethereum/web3.js/issues/566

The transaction gets signed correctly (string output below), but the From field is never populated, and I'm unable to set it in Go because it's an hidden struct field that is internally set by the EIP155Signer

tx before sign=
    TX(e694193e2f4d6dc099444ff0057456e23cafe0f8035c7c70daf688bc2bf5546a)
    Contract: false
    From:     [invalid sender: invalid sig]
    To:       b424f3bcc3da6f54f27f5f4af0c9c18d567702e6
    Nonce:    0
    GasPrice: 0x0
    GasLimit  0x0
    Value:    0x0
    Data:     0x746865626573746461746165766572
    V:        0x0
    R:        0x0
    S:        0x0
    Hex:      ec80808094b424f3bcc3da6f54f27f5f4af0c9c18d567702e6808f746865626573746461746165766572808080

signed tx=
    TX(ff6c011c7527f74e00fde94f6a4a5e523211f21f221c0b7133bf723486b3284c)
    Contract: false
    From:     [invalid sender: invalid sig]
    To:       b424f3bcc3da6f54f27f5f4af0c9c18d567702e6
    Nonce:    0
    GasPrice: 0x0
    GasLimit  0x0
    Value:    0x0
    Data:     0x746865626573746461746165766572
    V:        0x0
    R:        0x91a89e1ee55cc959572c050780301701c7f02436701db5961ccb01d556c2e708
    S:        0x699559f036a1153b2f979cd01ee9b0beb0e889c8aaab0dbd5a46dd7931842f02
    Hex:      f86c80808094b424f3bcc3da6f54f27f5f4af0c9c18d567702e6808f74686562657374646174616576657280a091a89e1ee55cc959572c050780301701c7f02436701db5961ccb01d556c2e708a0699559f036a1153b2f979cd01ee9b0beb0e889c8aaab0dbd5a46dd7931842f02

Seems that the sender can't be derived according to this source file when the transaction is printed: https://github.com/ethereum/go-ethereum/blob/8771c3061f340451d0966adcc547338a25f2231f/core/types/transaction.go#L273

I created a transaction in Go, signed it with a EIP155Signer signer, but when I try to publish the transaction through the Go client to the private blockchain, I get the error Invalid sender. Any idea what's happening here?

This issue seems to have the same error: https://github.com/ethereum/web3.js/issues/566

The transaction gets signed correctly (string output below), but the From field is never populated, and I'm unable to set it in Go because it's a hidden struct field that is internally set by the EIP155Signer

tx before sign=
    TX(e694193e2f4d6dc099444ff0057456e23cafe0f8035c7c70daf688bc2bf5546a)
    Contract: false
    From:     [invalid sender: invalid sig]
    To:       b424f3bcc3da6f54f27f5f4af0c9c18d567702e6
    Nonce:    0
    GasPrice: 0x0
    GasLimit  0x0
    Value:    0x0
    Data:     0x746865626573746461746165766572
    V:        0x0
    R:        0x0
    S:        0x0
    Hex:      ec80808094b424f3bcc3da6f54f27f5f4af0c9c18d567702e6808f746865626573746461746165766572808080

signed tx=
    TX(ff6c011c7527f74e00fde94f6a4a5e523211f21f221c0b7133bf723486b3284c)
    Contract: false
    From:     [invalid sender: invalid sig]
    To:       b424f3bcc3da6f54f27f5f4af0c9c18d567702e6
    Nonce:    0
    GasPrice: 0x0
    GasLimit  0x0
    Value:    0x0
    Data:     0x746865626573746461746165766572
    V:        0x0
    R:        0x91a89e1ee55cc959572c050780301701c7f02436701db5961ccb01d556c2e708
    S:        0x699559f036a1153b2f979cd01ee9b0beb0e889c8aaab0dbd5a46dd7931842f02
    Hex:      f86c80808094b424f3bcc3da6f54f27f5f4af0c9c18d567702e6808f74686562657374646174616576657280a091a89e1ee55cc959572c050780301701c7f02436701db5961ccb01d556c2e708a0699559f036a1153b2f979cd01ee9b0beb0e889c8aaab0dbd5a46dd7931842f02

Seems that the sender can't be derived according to this source file when the transaction is printed: https://github.com/ethereum/go-ethereum/blob/8771c3061f340451d0966adcc547338a25f2231f/core/types/transaction.go#L273