I was hoping to get a basic example running to get me started, and was hoping that these examples would work out of the box for this specific board. Is there perhaps an easy solution or something obvious that I'm missing?
the cause is a little hard to explain, it's a wierd interaction between dev-dependencies and optional features.
dev-dependencies are NOT used when building the lib crate, but they are enabled when building examples. however, it is NOT supported to mark dev-dependencies as optional, which means even not every example uses every crates of dev-dependencies, when you build any example, all the dev-dependencies are enabled.
specifically, the blinky_basic example doesn't depends on rtic, so it didn't have any required-features, but since rtic is listed in dev-dependencies, it will be enabled anyway. the problem is, the feature flags required by rtic are not enabled by default, but controlled by the rtic optional feature flag.
so you are facing a really peculiar situation, where the "simple" example blinky_basic gives unhelpful error message, but if you build the more "advanced" example blinky_rtic, you'll be instructed to enable the rtic feature, and it builds successfully when you enable that feature.
IMO, it's better to move the examples (at least those needs non-trivial configurations) into separate packages, because of the limitation of dev-dependencies.