vcpkg-empty-featureful-port[c] = combination-fails
vcpkg-empty-featureful-port[a] = cascade
vcpkg-empty-featureful-port[b] = feature-fails
vcpkg-empty-featureful-port[default-feature] = feature-fails
vcpkg-empty-featureful-port = fail
vcpkg-empty-featureful-port[core,a-default-feature,c] = combination-fails