Sync issue in VMR flow

[ViktorHofer]

See https://github.com/dotnet/dotnet/pull/220/files

This PR removes the dotnet10 feed even though it was added in dotnet/dotnet#182. It probably removes it because it treats the forward flow as newer. The backflow PR into scenario-tests wasn't yet merged: https://github.com/dotnet/scenario-tests/pull/234/files

I'm not sure why the forward flow is treated as newer given that it doesn't even bring in any source updates.

[ViktorHofer]

this is an interesting case - @premun @mmitche

[ViktorHofer]

In simpler terms: An additional change in a forward-flow PR gets overwritten by the next forward-flow PR if the repo origin doesn't have that change.

[premun]

Right, but I think we can't do anything about that really. Basically every conflict/decision needs to happen always on both sides because the repos are disconnected.

[ViktorHofer]

Right, but especially with everyBuild insertions for which the repo doesn't have a chance to merge the backflow PR with the update in time, all the manual changes in forward-flow PRs will get reverted with the subsequent flow.

Also I don't expect that backflow PRs will get merged instantly by the repo owners.

Unfortunately, I don't see the forward flow into the VMR working without a change here. In the best, the forward-flow build fails because of the revert and is blocked. In the worst case, the revert doesn't block the insertion and behavior changes unintentionally.

[premun]

I have to put together a timeline of what happened when to answer this. Things should not just revert on their own, only if a revert happens on either side, it will manifest on the other in the next flow, but that is by design.

[ViktorHofer]

Another instance:

dotnet/dotnet@e7dbf41 this commit was made 4 days ago and then 2 days ago reverted with the arcade forward flow PR: dotnet/dotnet@cfd94c6

This is causing all the prebuilt issues in the backflow PRs for repos that use Arcade 10.

cc @MichaelSimons