- Can depend conditionally based on variant, compiler, arch, deps, etc
- normalize() is not iterative yet: no chaining depends_ons
- really need a SAT solver, but iterative will at least handle
simple cases.
- Added "strict" option to Spec.satisfies()
- strict checks that ALL of other's constraints are met (not just
the ones self shares)
- Consider splitting these out into two methods: could_satisfy() and
satisfies()
- didn't do this yet as it would require changing code that uses
satisfies()
- Changed semantics of __contains__ to use strict satisfaction (SPACK-56)
- Added tests for optional dependencies.
- The constrain() method on Specs, compilers, versions, etc. now
returns whether the spec changed as a result of the call.
- Variants are now declarable in packages using the variant() directive.
- Variants are checked - you can't just ask for a random variant, it has to be declared.
- conditional logic (@when, if, '+debug' in spec, etc.) still required in package to
implement variant.
- New inclusive version ranges from git-fetching branch enable a fix.
- Can now write :1 to include 1.3, 1.4, etc.
- couldn't do this before so provides() was weird.
