What version of Turborepo are you using?

1.6.0.canary.0

What package manager are you using / does the bug impact?

npm

What operating system are you using?

Mac

Describe the Bug

I am trying to use the prune command which since 1.6.0 canary build also supports NPM v8. Only when I am trying the command turbo prune --scope=demo -vvv then I am getting the following error shown:

❯ turbo prune --scope=demo -vvv         
2022-10-19T03:33:14.981+0100 [ERROR] turbo: error: could not construct graph: 1 error occurred:
        * json: cannot unmarshal array into Go struct field NpmPackage.packages.engines of type map[string]string


 ERROR  could not construct graph: 1 error occurred:
        * json: cannot unmarshal array into Go struct field NpmPackage.packages.engines of type map[string]string

I have searched my package.json in my repo and the only one that includes a engines-property is the one located in the root which has the following value:

  "engines": {    "node": ">= 14"  },

If I remove this property from the package.json-file I am still getting this error. Could it be its reading more package.json files? Maybe in the node_modules-directories that could be problematic? If so, would it be possible to output the path/location problematic package.json's file?

Expected Behavior

Would be able to successfully prune the project when using NPM package manager

To Reproduce

I am working on a repo