user78972: I am building a simple p2pkh transaction using libbitcoin. Trying to pass it through my regtest node. I am getting the following error message.
error code: -26
error message:
16: mandatory-script-verify-flag-failed (Signature is found in scriptCode)

my transaction hash is as below:
01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006b483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000

Can anyone suggest what is happening here?? 
Please let me know if more information is required to understand the problem. 
Thank you.

user87716: A standard P2PKH requires the following script in scriptPubKey ref:
OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG

Your scriptPubkey is currently short and malformed.

a91450628702abb40cc5fee219b9c834f4126c41988487

Should be something like this:
76 a9 14 50628702abb40cc5fee219b9c834f4126c419884 88 ac

(Assuming the address you are trying to pay to is 18L369eeqGbPECD2C62nvP7BbvRazwdsQt. Also don't forget to change the variable integer indicating size of this script (the byte before this which is currently 0x17 but should be 0x19.

user64730: Even though this question is a bit old by now, it might be useful to add a couple of things for future readers who might encounter the same Signature is found in scriptCode error.
First, the error appears when the policy change introduced in commit 9dabfe49c0 is triggered.  Specifically, the error will fire when FindAndDelete() detects the signature being passed to a CHECK(MULTI)SIG(VERIFY) operation to exist in the scriptCode itself.
This will never (actually, with neglible probability) happen when a simple p2pkh script is being redeemed.
Secondly, the spending transaction and signature in the original question is in fact valid :
printf '%s\n' 01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006B483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000 '[{"txid":"0182D51218C56DB2D8D6826A2A846656D01B289C34637B497629995060AEF88D","vout":0,"scriptPubKey":"76A914E08E0B7AF54A0A5B4CA39ECC5430AB2730ECC2A188AC"}]' | regtest-cli -stdin signrawtransactionwithwallet 
{
  "hex": "01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006b483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000",
  "complete": true
}


78972: <p>I am building a simple p2pkh transaction using libbitcoin. Trying to pass it through my regtest node. I am getting the following error message.</p>

<pre><code>error code: -26
error message:
16: mandatory-script-verify-flag-failed (Signature is found in scriptCode)
</code></pre>

<p>my transaction hash is as below:</p>

<pre><code>01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006b483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000
</code></pre>

<p>Can anyone suggest what is happening here?? </p>

<p>Please let me know if more information is required to understand the problem. </p>

<p>Thank you.</p>
 87716: <p>A standard P2PKH requires the following script in scriptPubKey <a href="https://en.bitcoin.it/wiki/Script#Standard_Transaction_to_Bitcoin_address_.28pay-to-pubkey-hash.29" rel="nofollow noreferrer">ref</a>:</p>

<pre><code>OP_DUP OP_HASH160 &lt;pubKeyHash&gt; OP_EQUALVERIFY OP_CHECKSIG
</code></pre>

<p>Your scriptPubkey is currently short and malformed.</p>

<blockquote>
  <p>a91450628702abb40cc5fee219b9c834f4126c41988487</p>
</blockquote>

<p>Should be something like this:</p>

<pre><code>76 a9 14 50628702abb40cc5fee219b9c834f4126c419884 88 ac
</code></pre>

<p>(Assuming the address you are trying to pay to is <code>18L369eeqGbPECD2C62nvP7BbvRazwdsQt</code>. Also don't forget to change the variable integer indicating size of this script (the byte before this which is currently <code>0x17</code> but should be <code>0x19</code>.</p>
 64730: <p>Even though this question is a bit old by now, it might be useful to add a couple of things for future readers who might encounter the same <code>Signature is found in scriptCode</code> error.</p>

<p>First, the error appears when the policy change introduced in commit <code>9dabfe49c0</code> is triggered.  Specifically, the error will fire when <code>FindAndDelete()</code> detects the signature being passed to a <code>CHECK(MULTI)SIG(VERIFY)</code> operation to exist in the <code>scriptCode</code> itself.
This will never (actually, with neglible probability) happen when a simple <code>p2pkh</code> script is being redeemed.</p>

<p>Secondly, the spending transaction and signature in the original question is in fact valid :</p>

<pre><code>printf '%s\n' 01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006B483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000 '[{"txid":"0182D51218C56DB2D8D6826A2A846656D01B289C34637B497629995060AEF88D","vout":0,"scriptPubKey":"76A914E08E0B7AF54A0A5B4CA39ECC5430AB2730ECC2A188AC"}]' | regtest-cli -stdin signrawtransactionwithwallet 
{
  "hex": "01000000018df8ae6050992976497b63349c281bd05666842a6a82d6d8b26dc51812d58201000000006b483045022100c4befe583a3bc22eeaf1516c6d26fb3e1240bdfdf25db266494d82c77ccb36100220108ad79c4a34115eec23f5b0202d492dd88ec637df17a1982d4a63382e457599012102a018e21c743a4b67dcf38f9b693e807b1fbb833dfe705aa513abbf177b04adc2ffffffff01c0a6b9290100000017a91450628702abb40cc5fee219b9c834f4126c4198848700000000",
  "complete": true
}
</code></pre>
