Private Repositories and Public Mirrors URL link

[jcurl]

I have repositories locally on my BitBucket Server and mirrored on GitHub. I have the following refs:

• origin so that the command git config --get remote.origin.url returns ssh://bitbucket/netfw/RJCP.DLL.SerialPortStream.git. Note, that the SSH configuration (.ssh/config) I use maps the keyword bitbucket to the correct host name.
• github points to git@github.com:jcurl/SerialPortStream.git

I am trying to create using SourceLink a PDB that maps to github, not to my local (private) repository. On releases of my OSS packages I push to GitHub. I can't seem to get it to work, read various docs in the repository, tried to understand the implementation targets.

With:

<PropertyGroup>
  <RepositoryUrl>https://github.com/jcurl/RJCP.DLL.SerialPortStream</RepositoryUrl>
  <PackageProjectUrl>$(RepositoryUrl)</PackageProjectUrl>
  <PublishRepositoryUrl>true</PublishRepositoryUrl>
  <EmbedUntrackedSources>true</EmbedUntrackedSources>
  <IncludeSymbols>true</IncludeSymbols>
  <SymbolPackageFormat>snupkg</SymbolPackageFormat>
</PropertyGroup>

<PropertyGroup Condition="'$(Configuration)' == 'Release'">
  <DebugType>embedded</DebugType>
  <Optimize>true</Optimize>
  <Deterministic>true</Deterministic>
  <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
</PropertyGroup>

<ItemGroup>
  <PackageReference Include="RJCP.MSBuildTasks" Version="0.2.3" PrivateAssets="all"/>
  <PackageReference Include="Microsoft.SourceLink.BitBucket.Git" Version="1.1.1" PrivateAssets="all"/>
  <SourceLinkBitBucketGitHost Include="bitbucket" ContentUrl="https://devfxio.net/bitbucket"/>
</ItemGroup>

I confirm that the NuPacket repository URL is https://github.com, and the PDBs point correctly to my own internal webserver hosting my code.

If I use instead Microsoft.SourceLink.GitHub, how do I get the source links to point to the URLs https://raw.githubusercontent.com/jcurl/SerialPortStream, instead of https://raw.githubusercontent.com/netfw/RJCP.DLL.SerialPortStream? I couldn't figure out either how to use the advanced options of <SourceRoot>, or in which Target to define that in, if that is even the correct place?