<p>The nix cache is now located at cache.iog.io</p>
<p>With a <code>/etc/nix/nix.conf</code> (or <code>~/.config/nix/nix.conf</code>) that looks like this:</p>
<pre><code>experimental-features = nix-command flakes
allow-import-from-derivation = true
substituters = https://cache.nixos.org https://cache.iog.io
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
</code></pre>
<p>then you should have the binary cache from IOG working again.
(you many need to log out and log back in and or restart the nix daemon to get these changes to take)</p>
<p><a href="https://github.com/input-output-hk/cardano-node/blob/master/doc/getting-started/building-the-node-using-nix.md#iohk-binary-cache" rel="nofollow noreferrer">Doc source</a></p>

CC BY-SA 4.0
2022-12-04T03:32:12.820Z
thanks. So the nix-shell has been running for over an hour now. should it be taking so long?
tyvan266
CC BY-SA 4.0
2022-12-04T17:19:04.137Z
It depends on what is specified in the `shell.nix` but that doesn't sound like a good sign. If you can [build and run the cardano node as per these commands](https://github.com/input-output-hk/cardano-node/blob/master/doc/getting-started/building-the-node-using-nix.md#building-and-running-with-nix) in a few min you are pulling from the cache. You should also be able to see `cache.iog.io` in the output from nix.

Rebooting is also a sure fire way to make sure the new config has applied.
21eleven
CC BY-SA 4.0
2022-12-03T23:07:18.267Z
2022-12-03T23:07:18.267Z
21eleven
<p>You need to replace <code>hydra.iohk.io</code> with <code>cache.iog.io</code>, as the hydra server has been decommissioned.</p>
<p>Leave the key as it is: <code>f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=</code>.</p>

CC BY-SA 4.0
2022-12-03T20:59:42.740Z
thanks! however now i'm getting the error:

```
warning: ignoring untrusted substituter https://cache.iog.io
```
tyvan266
CC BY-SA 4.0
2022-12-03T21:28:58.653Z
I resolved the issue by changing substituter to `trusted-substituter`
tyvan266
CC BY-SA 4.0
2022-12-03T20:36:26.180Z
2022-12-03T20:36:26.180Z
Marek Mahut - StakeNuts
<p>I'm using <code>Ubuntu 20.04.5</code> with an <code>11th Gen Intel® Core™ i7-1195G7 @ 2.90GHz × 8</code>.</p>
<p>After cloning the plutus-apps repo and setting my nix config, i can't get pass the following nix-shell error:</p>
<pre><code>trace: To materialize project.plan-nix for haskell-project entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
warning: error: unable to download 'https://hydra.iohk.io/nix-cache-info': Timeout was reached (28); retrying in 280 ms
</code></pre>
<p>my etc/nix/nix.conf is set to the parameters from README.adoc :</p>
<pre><code>substituters        = https://hydra.iohk.io https://iohk.cachix.org https://cache.nixos.org/
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
extra-experimental-features = nix-command flakes 

</code></pre>
<p>any advice appreciated</p>
<p>Updates:</p>
<p>The compilation with nix-shell completed bringing me to</p>
<p><code>[nix-shell:~/Documents/Plutus/plutus-apps]$</code></p>
<p>However, along the way I get lots of warnings. Should I be concerned? For example:</p>
<pre><code>System/Remote/Snap.hs:7:1: warning: [-Wunused-imports]
    The import of ‘&lt;$&gt;’ from module ‘Control.Applicative’ is redundant
  |
7 | import Control.Applicative ((&lt;$&gt;), (&lt;|&gt;))
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
</code></pre>

<plutus><nix-shell>
Nix-shell in plutus-apps
# Nix-shell in plutus-apps

(Asked by: username_0 on 2022-12-03)

I'm using Ubuntu 20.04.5 with an 11th Gen Intel® Core™ i7-1195G7 @ 2.90GHz × 8.
After cloning the plutus-apps repo and setting my nix config, i can't get pass the following nix-shell error:
trace: To materialize project.plan-nix for haskell-project entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
warning: error: unable to download 'https://hydra.iohk.io/nix-cache-info': Timeout was reached (28); retrying in 280 ms

my etc/nix/nix.conf is set to the parameters from README.adoc :
substituters        = https://hydra.iohk.io https://iohk.cachix.org https://cache.nixos.org/
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
extra-experimental-features = nix-command flakes 


any advice appreciated
Updates:
The compilation with nix-shell completed bringing me to
[nix-shell:~/Documents/Plutus/plutus-apps]$
However, along the way I get lots of warnings. Should I be concerned? For example:
System/Remote/Snap.hs:7:1: warning: [-Wunused-imports]
    The import of ‘<$>’ from module ‘Control.Applicative’ is redundant
  |
7 | import Control.Applicative ((<$>), (<|>))
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Tags:** plutus, nix-shell

---

## 2 answers

### Answer by username_1 on 2022-12-03. Score: 2 | Accepted answer

The nix cache is now located at cache.iog.io
With a /etc/nix/nix.conf (or ~/.config/nix/nix.conf) that looks like this:
experimental-features = nix-command flakes
allow-import-from-derivation = true
substituters = https://cache.nixos.org https://cache.iog.io
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=

then you should have the binary cache from IOG working again.
(you many need to log out and log back in and or restart the nix daemon to get these changes to take)
Doc source

> **Comments:**
> **username_0**: thanks. So the nix-shell has been running for over an hour now. should it be taking so long?  
> **username_1**: It depends on what is specified in the `shell.nix` but that doesn't sound like a good sign. If you can [build and run the cardano node as per these commands](https://github.com/input-output-hk/cardano-node/blob/master/doc/getting-started/building-the-node-using-nix.md#building-and-running-with-nix) in a few min you are pulling from the cache. You should also be able to see `cache.iog.io` in the output from nix.  Rebooting is also a sure fire way to make sure the new config has applied.  

---

### Answer by username_2 on 2022-12-03. Score: 0

You need to replace `hydra.iohk.io` with `cache.iog.io`, as the hydra server has been decommissioned.

Leave the key as it is: `f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=`.

> **Comments:**
> **username_0**: thanks! however now i'm getting the error:  ``` warning: ignoring untrusted substituter https://cache.iog.io ```  
> **username_0**: I resolved the issue by changing substituter to `trusted-substituter`  

---

