Comment 30 for bug 1335323

PS: regarding the number of times (find-system "asdf") is called, mind that each defsystem-depends-on dependency does generate a call to operate and thus such a call to (find-system "asdf"). Once again, this should be innocuous and handled by the cache. If however, you update the asdf code and blow the cache in the middle of the build, it may be upgraded mid-build and then all bets are off and it might all blow up.