Update dotnet-core-desktop.yml

Author: dustinsoftware

.github/workflows/dotnet-core-desktop.yml

@@ -37,12 +37,12 @@ jobs:
       uses: microsoft/setup-msbuild@2008f912f56e61277eefaac6d1888b750582aa16
 
     - name: Build
-      run: msbuild build.proj /p:PackageOutputDir="nuget-output" /p:Configuration=${{ matrix.configuration }}
+      run: msbuild build.proj /p:PackageOutputDir="${{ env.GITHUB_WORKSPACE }}/nuget-output" /p:Configuration=${{ matrix.configuration }}
       env:
         Configuration: ${{ matrix.configuration }}
 
     - name: Upload build artifacts
       uses: actions/upload-artifact@v1
       with:
         name: Nuget Package
-        path: nuget-output
+        path: "${{ env.GITHUB_WORKSPACE }}/nuget-output"