error NU***0***: Unable to find package <packageId>. No packages exist with this id in source(s): github, nuget.org

Question

A project that useses public NUGET.ORG packages and also packages from my Org's ownnuget Github Packages registry restores just fine locally, but fails to do so inside a Github Action. Here's the exerpt from the action's yml:

name: workflow1

on:
  push:
    branches: [ main ]

jobs:

  build:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: write
      packages: write
      issues: write

    steps:
      - name: Check that shit out
        uses: actions/checkout@v3
      
      - name: Set that shit up
        uses: actions/setup-dotnet@v2
        with:
          dotnet-version: '6.x.x'

      - name: Build that shit
        run: |
          dotnet nuget add source https://nuget.pkg.github.com/myorg/index.json -n github -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }} --store-password-in-clear-text
          dotnet restore ./project.sln
          dotnet build ./project.sln --no-restore --configuration Release --nologo

Adding the nuget source is the same as recommended (as working) here. Unfortunately the Build step fails with an error like this

error NU***0***: Unable to find package <packageId>. No packages exist with this id in source(s): github, nuget.org 

I have also tried using a dedicated nuget.config file instead of expicitly adding the source on the run. This also fails, but curiously, the Github Packages registry is not even listed.

In other workflows I am also using the GITHUB_TOKEN to publish/write to the Gihub Packages registry. Now I only need to read from it, but the permissions should be okay I guess.

Any thoughts on why this keeps crahing? Any help is appreciated! Thanks.

Answer 1

Solved it now by myself. Posting here so it might be useful for someone else.

create nuget.config at project root, include a packageSourceMapping section.

<?xml version="1.0" encoding="utf-8"?>
<configuration>

  <packageSources>
    <clear />
    <add key="nuget" value="https://api.nuget.org/v3/index.json" />
    <add key="github" value="https://nuget.pkg.github.com/myOrg/index.json" />
  </packageSources> 

  <packageSourceMapping>

    <packageSource key="github">
      <package pattern="packageId" />
    </packageSource>

    <packageSource key="nuget">
      <package pattern="*" />
    </packageSource>
    
  </packageSourceMapping>

</configuration>

update the source's credentials on-the-fly in the GH action's execution

name: ci

on:
  push:
    branches: [ main ]

jobs:

  build:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: write
      issues: write

    steps:
      - name: Check that shit out
        uses: actions/checkout@v3
      
      - name: Set that shit up
        uses: actions/setup-dotnet@v2
        with:
          dotnet-version: '6.x.x'

      - name: Build that shit
        run: |
          dotnet nuget update source github -u ${{ github.actor }} -p ${{ secrets.READ_GH_PACKAGES_PAT_ORG }} --store-password-in-clear-text
          dotnet restore ./project.sln
          dotnet build ./project.sln --no-restore --configuration Release --nologo

Note, that in my case I couldn't use the built-in ${{ secrets.GITHUB_TOKEN }} and had to create one myself, since the repo containing the registry is private and not public. I also had to authorize the token for use within my organisation.