- Variant concretization is tricky:
- During concretization, a spec without variants (e.g., mpich) means
"don't care". So, Spec('mpich').satisfies('mpich+debug') is true
because it *could* still be built that way.
- After concretization, a spec without a particular variant means
"don't know", as that wasn't part of the spec, so the opposite
relationship is true. Assume 'spec' is already installed:
spec.satisfies('mpich+debug')
this is false beacuse the `debug` variant didn't exist when spec
was built, so we can't satisfy the explicit request for +debug.
535c1fac87