`overrideFeatureInstallOrder` gets confused when higher-priority features have dependencies

[dgholz]

I wanted to install features in a specific order, and used overrideFeatureInstallOrder to do that. I was surprised when the feature I wanted to install last installed first!

I have a minimal reproduction at https://github.com/dgholz/devcontainer-install-override

In the devcontainer.json file, I have:

{
    "image": "mcr.microsoft.com/devcontainers/base:trixie",
    "features": {
        "./features/use-tr": {},
        "./features/remove-tr": {}
    },
    "overrideFeatureInstallOrder": [
      "./features/use-tr",
      "./features/remove-tr"
    ]
}

But use-tr has a dependency on the common feature, and remove-tr does not. So when computeDependsOnInstallationOrder runs, it gets tripped up by

cli/src/spec-configuration/containerFeaturesOrder.ts

Line 625 in 997a2db

// If the node has no hard/soft dependencies, the node can always be installed.

use-tr gets excluded, and remove-tr has round priority 1 so gets installed before common (which has round priority 0)

The fix is to either set the round priority transitively (so common would get round priority 2 from use-tr); or to reverse the calculated priority ordering, so features with no dependencies would be installed first.

[dgholz]

The workaround is very simple: adding ./features/common as the first entry to overrideFeatureInstallOrder. But that feels a bit clunky, I have to track the transitive dependencies for all the features I am using.

I could also add a installsAfter to remove-tr, which would work fine for my minimal reproduction. You can assume that the real use case that inspired this issue is using features I do not have control over.