<p>You can get away with the mismatch between the ghc nix derivations: Tell Nix to use the IOHK binary cache. (It is indeed indicated as &quot;IMPORTANT&quot; the we should enable the IOHK binary cache at the top of the Plutus README file)</p>
<p>On tradition linuxes, that should do it:</p>
<pre><code>sudo mkdir -p /etc/nix
cat &lt;&lt;EOF | sudo tee /etc/nix/nix.conf
substituters = https://cache.nixos.org https://hydra.iohk.io
trusted-public-keys = iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
EOF
</code></pre>
<hr>
On NixOs:
<pre><code># configuration.nix
{ config, pkgs, ... }:
{
  # ... all the rest of the configuration of the server

  # iohk binary caches
  nix = 
  {
    binaryCaches          = [ &quot;https://hydra.iohk.io&quot; &quot;https://iohk.cachix.org&quot; ];
    binaryCachePublicKeys = [ &quot;hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=&quot; &quot;iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo=&quot; ];
  };
}
</code></pre>

CC BY-SA 4.0
2021-05-06T21:44:29.527Z
2021-05-07T05:56:24.393Z
2021-05-07T05:56:24.393Z
Stephane Rolland
<p>I keep getting the Hash Mismatch Error, anyway I can resolve it or get around it?</p>
<pre><code>hash mismatch in fixed-output derivation '/nix/store/7y3jr1jvzkj2146h7sivw0sfr2bhap3j-ghc-8.4.4-x86_64-deb8-linux.tar.xz':
wanted: sha256:06mb0l3y3gbs8znafxskzrkvgf2wbl0m22xsxhs3wzvbyxbqhajc
got:    sha256:0nx6459adisd4p5mjb03yp5jbaxplkjvwzfgkyw3bmwb3g9fgi9j
cannot build derivation '/nix/store/p68295cg7f09il07dsjpyskkmw9ms22f-ghc-8.4.4.drv': 1 dependencies couldn't be built
</code></pre>

CC BY-SA 4.0
2021-05-05T18:18:03.323Z
can you post the steps you have tried and the platform in which you are tying please
raghu
<plutus><nix>
Hash MisMatch Error on Plutus and Nix
# Hash MisMatch Error on Plutus and Nix

(Asked by: username_0 on 2021-05-05)

I keep getting the Hash Mismatch Error, anyway I can resolve it or get around it?
hash mismatch in fixed-output derivation '/nix/store/7y3jr1jvzkj2146h7sivw0sfr2bhap3j-ghc-8.4.4-x86_64-deb8-linux.tar.xz':
wanted: sha256:06mb0l3y3gbs8znafxskzrkvgf2wbl0m22xsxhs3wzvbyxbqhajc
got:    sha256:0nx6459adisd4p5mjb03yp5jbaxplkjvwzfgkyw3bmwb3g9fgi9j
cannot build derivation '/nix/store/p68295cg7f09il07dsjpyskkmw9ms22f-ghc-8.4.4.drv': 1 dependencies couldn't be built

**Tags:** plutus, nix
> **Comments:**
> **username_1**: can you post the steps you have tried and the platform in which you are tying please  

---

## 1 answers

### Answer by username_2 on 2021-05-06. Score: 1 | Accepted answer

You can get away with the mismatch between the ghc nix derivations: Tell Nix to use the IOHK binary cache. (It is indeed indicated as "IMPORTANT" the we should enable the IOHK binary cache at the top of the Plutus README file)
On tradition linuxes, that should do it:
sudo mkdir -p /etc/nix
cat <

On NixOs:
# configuration.nix
{ config, pkgs, ... }:
{
  # ... all the rest of the configuration of the server

  # iohk binary caches
  nix = 
  {
    binaryCaches          = [ "https://hydra.iohk.io" "https://iohk.cachix.org" ];
    binaryCachePublicKeys = [ "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=" "iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo=" ];
  };
}


---

