->>> not the cwd. I could conditionalize the use of `Cwd` on
->>> `wikistatedir` not being absolute, though, which in practice
->>> will only happen for unusual deployments (like the docwiki);
->>> or I could add some mechanism by which you can add a
->>> cwd-relative underlay? --s
+>>> not the cwd.
+>>>
+>>> The updated branch only loads `Cwd` if the path is relative;
+>>> an extra commit on branch `smcv/transient-relative` goes
+>>> behind `add_underlay`'s back to allow use of a cwd-relative
+>>> underlay. Which direction would you prefer? --s