Why am I getting warning NU1507 with Central Package Management even with Package Source Mapping set? - visual-studio

Question

I'm trying out the new Central Package Management feature in NuGet.
As stated in the documentation, if you use multiple NuGet sources (which I use), it is now required to configure the Package Source Mapping in a nuget.config file, otherwise you should get a NU1507 warning.
My simplified file tree is this:
MySolution.sln
Proj1.csproj
MyLibrary\ (this is an external repository with all my shared projects)
Directory.Packages.props
nuget.config
Proj2\ (an example library project)
Proj2.csproj
Here is the Proj1.csproj content:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net7.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
<PropertyGroup>
<DefaultItemExcludes>$(DefaultItemExcludes);MyLibrary\**\*</DefaultItemExcludes>
</PropertyGroup>
</Project>
Here is Directory.Packages.props:
<Project>
<PropertyGroup>
<ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
</PropertyGroup>
<ItemGroup>
<PackageVersion Include="JetBrains.Annotations" Version="2022.1.0" />
</ItemGroup>
</Project>
Here is nuget.config:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
<clear/>
<add key="nuget.org" value="https://api.nuget.org/v3/index.json"/>
<add key="Custom NuGet" value="https://nuget.mydomain.net/"/>
</packageSources>
<packageSourceMapping>
<packageSource key="nuget.org">
<package pattern="*"/>
</packageSource>
<packageSource key="Custom NuGet">
<package pattern="MyNamespace.*"/>
</packageSource>
</packageSourceMapping>
</configuration>
and Proj2.csproj:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net7.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
</Project>
In the official documentation the MyLibrary\nuget.config should be used when restoring the packages because it is in the parent directory of Proj2.csproj, and actually it works when I build the solution via dotnet build, but when I build it in Visual Studio I still get the NU1507 warning.
I know that I could work around the issue by copying the nuget.config file in the same directory as the solution file (the warning goes away), but I have hundreds of projects that include the MyLibrary directory and I'd like to keep all the configuration centralized.
Moreover it works as expected when it's built from the command line, so what am I doing wrong?

Answer 1

Everything seems like correct from your configure file.But MS doc has mentioned this note:Central package management is in active development. You can provide any feedback you may have at Nuget/Home
Here’re suggestions you can have a try to check :
1 check your visual studio version and this feature is available for Visual Studio 2022.17.2 and later.Because older tooling will ignore central package management configurations and features.See more information please refer to doc:CPM
2 If you are unable to onboard to Package Source Mapping but want to use central package management, can suppress the warning. Please refer to doc:
<PropertyGroup>
<NoWarn>$(NoWarn);NU1507</NoWarn>
</PropertyGroup>
3 use dotnet nuget list source to get package source list and check whether they are enabled.