Resolve to the newest version satisfying the constraint (default; preserves the historic behavior).
Resolve to the oldest version satisfying the constraint.
Resolve to the version installed on the analyzing system (needs R; falls back to newest when unavailable).
How a constrained dependency (e.g.
Imports: quantmod (>= 0.4-9)) is resolved to a concrete version against the signature database (seesolver.sigdb.versionSelection).