What are they bisecting with? FreeBSD uses CVS and Perforce.

These items in the slide don't add up:

> Things had worked accidentally for years, due to linkerset alphabetical ordering

In other words, the real bug is many years old. Yet, on the last slide:

> Since we found the bug within a week or so of it hitting the tree, the developer responsible was incredibly responsive. All the details were fresh in his memory.

What? Wasn't what hit the tree the ordering change which exposed the bug? It doesn't seem like that being fresh in anyone's mind is of much help.