Faré wrote:
For defsystem-depends-on dependencies, there's asdf::system-defsystem-depends-on aka asdf/system:system-defsystem-depends-on in ASDF3. Unhappily, the slot is sometimes unbound (e.g. for preloaded systems), which is probably a bug (Robert, are you on it?), and you need to test for (slot-boundp system 'asdf::defsystem-depends-on) (exported from asdf/component — why isn't it in asdf/system? That's probably another bug. That said, it shouldn't be "just fixed" without running the upgrade test — I believe a :recycle asdf/component is then needed in asdf/system. At the very least, it should be flagged for fixing in case there's ever a backward-incompatible ASDF4).
https://bugs.launchpad.net/asdf/+bug/1247662
Cheers, r