opentelemetry-dotnet/docs/trace/building-your-own-processor/building-your-own-processor.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <ItemGroup>
    <!--
    <PackageReference Include="OpenTelemetry" Version="$(OpenTelemetryPkgVer)" />
    -->
    <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry\OpenTelemetry.csproj" />
  </ItemGroup>
</Project>