<p>Regtest mode was introduced in version 0.9.0, via pull request <a href="https://github.com/bitcoin/bitcoin/pull/2632" rel="nofollow noreferrer">#2632</a>. That is why it doesn't work in 0.8.1, as you noticed. There is no other option to run regtest in that version, although testnet3 is supported by that version so you should still be able to use that if it suits your needs. Otherwise just upgrade to a newer version which will contain performance improvements, bugfixes and newer feature support :)</p>

CC BY-SA 3.0
2017-11-27T12:18:36.830Z
Oh.. okay!

I was trying to do some tests with some code that was removed from the core, and that was the newest version including the code.

For other tests i'm using v0.15.1 in regtest and testnet too, depending the necessities.

Thanks!
Carlos GC
CC BY-SA 3.0
2017-11-27T12:00:04.233Z
2017-11-27T12:00:04.233Z
meshcollider
<p>I'm trying to run bitcoin-core v0.8.1 in regtest mode, but it doesn't work.
When placing regtest=1 in bitcoin.conf it starts to sync the mainnet.
I've not seen anything related in the code.</p>

<p>So I was wondering if there's any configuration different to run regtest mode in that version different from more recent ones.</p>

<p>When was regtest mode added ?</p>

CC BY-SA 3.0
2017-11-28T00:40:08.773Z
May I ask why you're interested in using such an old version? Depending on your goal, another approach may be better.
Pieter Wuille
CC BY-SA 3.0
2017-11-28T21:08:19.710Z
Sure!
I'm making some tests with the disabled opcodes re-enabling them again. And realised that the 0.8.1 was the last version where them were coded, so it was easy to "enable" them. I just coded the bitwise logic ones in the current version, but the arithmetic ones were difficult, so i tried to run the 0.8.1.
Carlos GC
<bitcoin-core><regtest>
Can I use run Bitcoin Core in regtest mode in v0.8.1?
Carlos GC
# Can I use run Bitcoin Core in regtest mode in v0.8.1?

(Asked by: username_0 on 2017-11-27)

I'm trying to run bitcoin-core v0.8.1 in regtest mode, but it doesn't work.
When placing regtest=1 in bitcoin.conf it starts to sync the mainnet.
I've not seen anything related in the code.

So I was wondering if there's any configuration different to run regtest mode in that version different from more recent ones.

When was regtest mode added ?

**Tags:** bitcoin-core, regtest

> **Comments:**
> **username_1**: May I ask why you're interested in using such an old version? Depending on your goal, another approach may be better.  
> **username_0**: Sure! I'm making some tests with the disabled opcodes re-enabling them again. And realised that the 0.8.1 was the last version where them were coded, so it was easy to "enable" them. I just coded the bitwise logic ones in the current version, but the arithmetic ones were difficult, so i tried to run the 0.8.1.  

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## 1 answers

### Answer by username_2 on 2017-11-27. Score: 0 | Accepted answer

Regtest mode was introduced in version 0.9.0, via pull request [#2632](https://github.com/bitcoin/bitcoin/pull/2632). That is why it doesn't work in 0.8.1, as you noticed. There is no other option to run regtest in that version, although testnet3 is supported by that version so you should still be able to use that if it suits your needs. Otherwise just upgrade to a newer version which will contain performance improvements, bugfixes and newer feature support :)

> **Comments:**
> **username_0**: Oh.. okay!  I was trying to do some tests with some code that was removed from the core, and that was the newest version including the code.  For other tests i'm using v0.15.1 in regtest and testnet too, depending the necessities.  Thanks!  

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