user5556: I have successfully installed nix, cabal and have setup the IOHK binary cache. I cloned the plutus-app repository and successfully built the Haskell packages and other artifacts with nix. Then running nix-shell successfully I get into the nix-shell prompt:
[nix-shell:/home/datapool/plutus-apps]$

I then issue the following commands:
[nix-shell:/home/datapool/plutus-apps]$ cd plutus-playground-client
[nix-shell:/home/datapool/plutus-apps/plutus-playground-client]$ npm run start

I then get this output:
> plutus-playground-client@1.0.0 start /home/datapool/plutus-apps/plutus-playground-client
> plutus-playground-generate-purs && npm install && npm run install:spago && npm run build:webpack:dev

 /nix/store/ry2hywgh6cmmm9d5b9566nxdskd752yc-plutus-playground-generate-purs/bin/plutus-playground-generate-purs: line 6: /bin/plutus-playground-server: No such file or directory
 npm ERR! code ELIFECYCLE
 npm ERR! syscall spawn
 npm ERR! file sh
 npm ERR! errno ENOENT
 npm ERR! plutus-playground-client@1.0.0 start: `plutus-playground-generate-purs && 
 npm install && npm run install:spago && npm run build:webpack:dev`
 npm ERR! spawn ENOENT
 npm ERR! 
 npm ERR! Failed at the plutus-playground-client@1.0.0 start script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

 npm ERR! A complete log of this run can be found in:
 npm ERR!     /home/brightchip/.npm/_logs/2022-01-12T13_05_31_245Z-debug.log

As the output says, it seems to be looking for a non-existent /bin/plutus-playground-server.
Same problem when I run the server:
[nix-shell:/home/datapool/plutus-apps/plutus-playground-client]$ plutus-playground-server
plutus-playground-server: for development use only
/nix/store/fm77y43lzpgnay4pyc48jwpln0lnmrk3-plutus-playground-server/bin/plutus-playground-server: line 10: /bin/plutus-playground-server: No such file or directory

Any idea what I might be missing or how to debug?

user6004: Looks related to an issue I ran into where the directories were missing.
I needed to git checkout a patch.
Possible solution - https://cardano.stackexchange.com/a/6251/6004
The instructions are at :
https://tutorials.cardanoacademy.io/plutus-pioneer-program/setting-up-plutus-playground/cloning-plutus-repository

user5556: Thanks. The patch works:
git checkout 3746610e53654a1167aeb4c6294c6096d16b0502


5556: <p>I have successfully installed nix, cabal and have setup the IOHK binary cache. I cloned the plutus-app repository and successfully built the Haskell packages and other artifacts with nix. Then running nix-shell successfully I get into the nix-shell prompt:</p>
<pre><code>[nix-shell:/home/datapool/plutus-apps]$
</code></pre>
<p>I then issue the following commands:</p>
<pre><code>[nix-shell:/home/datapool/plutus-apps]$ cd plutus-playground-client
[nix-shell:/home/datapool/plutus-apps/plutus-playground-client]$ npm run start
</code></pre>
<p>I then get this output:</p>
<pre><code>&gt; plutus-playground-client@1.0.0 start /home/datapool/plutus-apps/plutus-playground-client
&gt; plutus-playground-generate-purs &amp;&amp; npm install &amp;&amp; npm run install:spago &amp;&amp; npm run build:webpack:dev

 /nix/store/ry2hywgh6cmmm9d5b9566nxdskd752yc-plutus-playground-generate-purs/bin/plutus-playground-generate-purs: line 6: /bin/plutus-playground-server: No such file or directory
 npm ERR! code ELIFECYCLE
 npm ERR! syscall spawn
 npm ERR! file sh
 npm ERR! errno ENOENT
 npm ERR! plutus-playground-client@1.0.0 start: `plutus-playground-generate-purs &amp;&amp; 
 npm install &amp;&amp; npm run install:spago &amp;&amp; npm run build:webpack:dev`
 npm ERR! spawn ENOENT
 npm ERR! 
 npm ERR! Failed at the plutus-playground-client@1.0.0 start script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

 npm ERR! A complete log of this run can be found in:
 npm ERR!     /home/brightchip/.npm/_logs/2022-01-12T13_05_31_245Z-debug.log
</code></pre>
<p>As the output says, it seems to be looking for a non-existent /bin/plutus-playground-server.</p>
<p>Same problem when I run the server:</p>
<pre><code>[nix-shell:/home/datapool/plutus-apps/plutus-playground-client]$ plutus-playground-server
plutus-playground-server: for development use only
/nix/store/fm77y43lzpgnay4pyc48jwpln0lnmrk3-plutus-playground-server/bin/plutus-playground-server: line 10: /bin/plutus-playground-server: No such file or directory
</code></pre>
<p>Any idea what I might be missing or how to debug?</p>
 6004: <p>Looks related to an issue I ran into where the directories were missing.
I needed to git checkout a patch.</p>
<p>Possible solution - <a href="https://cardano.stackexchange.com/a/6251/6004">https://cardano.stackexchange.com/a/6251/6004</a></p>
<p>The instructions are at :</p>
<p><a href="https://tutorials.cardanoacademy.io/plutus-pioneer-program/setting-up-plutus-playground/cloning-plutus-repository" rel="nofollow noreferrer">https://tutorials.cardanoacademy.io/plutus-pioneer-program/setting-up-plutus-playground/cloning-plutus-repository</a></p>
 5556: <p>Thanks. The patch works:</p>
<pre><code>git checkout 3746610e53654a1167aeb4c6294c6096d16b0502
</code></pre>
