darc update-dependencies --coherency-only fails to find updates

[riarenas]

• This issue is blocking
• This issue is causing unreasonable pain

It seems like when passing the --coherency-only flag to the update-dependencies command is not finding all the expected required coherency updates.

Repro steps

1. check out dotnet/installer@aeb5322
2. darc update-dependencies --channel ".NET 8.0.1xx SDK"--coherency-only

Expected
Darc should find that coherency fails, report which assets need to be fixed up.

Checking for coherency updates...
Using 'Strict' coherency mode. If this fails, a second attempt utilizing 'Legacy' Coherency mode will be made.
Coherency updates failed for the following dependencies:
  Unable to update Microsoft.NET.Workload.Emscripten.Current.Manifest-8.0.100-preview.2 to have coherency with Microsoft.NETCore.App.Runtime.win-x64: https://github.com/dotnet/runtime @ c7537bdf261a7160836447ec46e1f136580a9fe4 does not contain dependency Microsoft.NET.Workload.Emscripten.Current.Manifest-8.0.100-preview.2
    - Add the dependency to https://github.com/dotnet/runtime.
    - Pin the dependenency.
    - Remove the CoherentParentDependency attribute.
  Unable to update Microsoft.NET.Workload.Emscripten.net7.Manifest-8.0.100-preview.2 to have coherency with Microsoft.NETCore.App.Runtime.win-x64: https://github.com/dotnet/runtime @ c7537bdf261a7160836447ec46e1f136580a9fe4 does not contain dependency Microsoft.NET.Workload.Emscripten.net7.Manifest-8.0.100-preview.2
    - Add the dependency to https://github.com/dotnet/runtime.
    - Pin the dependenency.
    - Remove the CoherentParentDependency attribute.
  Unable to update Microsoft.NET.Workload.Emscripten.net6.Manifest-8.0.100-preview.2 to have coherency with Microsoft.NETCore.App.Runtime.win-x64: https://github.com/dotnet/runtime @ c7537bdf261a7160836447ec46e1f136580a9fe4 does not contain dependency Microsoft.NET.Workload.Emscripten.net6.Manifest-8.0.100-preview.2
    - Add the dependency to https://github.com/dotnet/runtime.
    - Pin the dependenency.
    - Remove the CoherentParentDependency attribute.
Attempting fallback to Legacy coherency

Actual
Darc finds no dependencies to update

Checking for coherency updates...
Using 'Strict' coherency mode. If this fails, a second attempt utilizing 'Legacy' Coherency mode will be made.
Found no dependencies to update.

Release Note Category

• Feature changes/additions
• Bug fixes
• Internal Infrastructure Improvements

Release Note Description