[racket] bug in package migration?

I upgraded to 6.0.1 and migrated my installed packages (via the gui), but the doco for them is all gone.  It's all the stuff in ~/Library/Racket/snapshot. Looks like the generic top level stuff is there, and no packages.

The top level local doco page has an entry "Racket Generic Graph Library" and it links to file:///Users/ryan/Library/Racket/snapshot/pkgs/graph/graph/doc/graph/index.html but `pkgs` doesn't exist.

Is there something else I should do to ensure the doco gets re-cached?