Both the linker tests and the singlefile tests use a prebuilt version of the host instead of the live built one. In general we want to use live built assets where possible. In addition to that, when the repository revs to the next major version and the SDK doesn't yet understand the net7.0 tfm, the prebuilt host isn't discovered without help (KnownAppHostPack
AppHostPackVersion update).
TL;DR: Tests which depend on the apphost should have a dependency on the host subset being built first.