[racket-dev] Strange module mismatch

I'm hitting a module mismatch that won't go away no matter how many
times I type raco make or raco setup.

Running the module

#lang racket
(require redex)
variables-not-in

produces

link: module mismatch, probably from old bytecode whose dependencies
have changed: variable not provided (directly or indirectly) from
module: "/Users/clklein/git/plt/collects/redex/private/fresh.rkt"
accessed from module: 'anonymous-module at source phase level: 0 in:
variables-not-in

in DrRacket but works fine using the racket command.

This happens in a fresh build of master's HEAD.