port 1.300 builds all dependencies regardless of state

[yaseppochi (Stephen J. Turnbull)]

using port -u -f all dependencies get rebuilt unconditionally. this gives absurdities like

Warning: Uninstall forced. Proceeding despite dependencies. ---> Deactivating readline 5.0.005_0 ---> Uninstalling readline 5.0.005_0 ---> Packaging tgz archive for readline 5.0.005_0 ---> Installing readline 5.0.005_0 ---> Activating readline 5.0.005_0

At least it finds the existing distribution tarballs.

This has been observed just now for sqlite (which didn't need an upgrade but got rebuilt, as well as readline the dependency---the missing "3" was a typo) and sqlite3 (which did need an upgrade), and for several GNOME packages (all libraries) a few days ago.

"port upgrade graphviz" just now only rebuilt graphviz (thank heavens, since it depends on X).

port's dependency algorithms seem really fragile and often unintuitive.