Unable to find Pnpm, does it exist ? On Scalingo

[Rob1d]

Describe the bug
Hi ! I used your buildpack since 1 year with my entreprise project in the plateform Scalingo. But the last week the buildpack doesn't want to build, meanwhile I've used it for hundreds of builds and changed nothing in my pnpm config. To be more precise I got an error at the second step of the build, when he needs to install pnpm, it says that it's unable to find pnpm.

here is the full log from scalingo

<-- Start deployment of marcel-dev -->
Fetching source code
-----> Cloning custom buildpack: https://github.com/unfold/heroku-buildpack-pnpm#master
Fail to clone the 'master' branch, attempt to clone the 'main' branch
-----> Cloning custom buildpack: https://github.com/unfold/heroku-buildpack-pnpm#main

-----> Creating runtime environment

   NPM_CONFIG_LOGLEVEL=error
   NODE_VERBOSE=false
   NODE_ENV=production
   NODE_MODULES_CACHE=true

-----> Installing binaries
engines.node (package.json): 20.17.0
engines.npm (package.json): unspecified (use default)
engines.pnpm (package.json): unspecified (use default)

   Resolving node version 20.17.0...
   Downloading and installing node 20.17.0...
   Detected package-lock.json: defaulting npm to version 5.x.x
   Bootstrapping npm 5.x.x (replacing 10.8.2)...
   npm 5.x.x installed
   Downloading and installing pnpm...
   Unable to install pnpm ; does it exist?

-----> Build failed

   We're sorry this build is failing! You can troubleshoot common issues here:
   https://devcenter.heroku.com/articles/troubleshooting-node-deploys
   
   If you're stuck, please submit a ticket so we can help:
   https://help.heroku.com/
   
   Love,
   Heroku

To Reproduce
Steps to reproduce the behavior:

1. Go to scalingo
2. Make a build
3. Check the build log
4. See error

Versions

• Node Version: 20.17.0
• Pnpm version : 9.5.0
• Buildpack Version: latest

Additional context
Thanks and have a great day !

[navidemad]

Have you tried the official https://github.com/Scalingo/nodejs-buildpack.
Apparently it supports pnpm for few months already: https://github.com/Scalingo/nodejs-buildpack/pull/115/files#diff-06572a96a58dc510037d5efa622f9bec8519bc1beab13c9f251e97e657a9d4edR21